Complaint sub-issue: Credit card company isn't resolving a dispute about a purchase on your statement

On XX/XX/2020 I purchased as a gift, the XXXX XXXX XXXX XXXX Model # XXXX @ {$1000.00}, XXXX XXXX XXXX XXXX XXXX Model # XXXX @ {$1000.00}, XXXX XXXX XXXX XXXX  and Installation Package @ {$350.00}. The bill of sale totaled {$2600.00}. One-half ( 1/2 ) of the total - {$1300.00} was charged to XXXX XXXX and the balance - {$1300.00} was charged to the merchants financial Citi Brand Source charge card. 
XX/XX/2020 The merchants delayed install & stock availability, resulted in only a partial delivery & install of the brand new out-of-box appliances to the gift recipients residence. 
XX/XX/2020 After a two-day window was established by the merchant, a follow up delivery and install were made to the gift recipients residence. 
XX/XX/2020 While preparing the newly installed appliances for use on this date, ( neither of the appliances were in use on or prior to this date ) one of the glass shelves exploded in the hands of the owner/recipient of this appliance. Simultaneously, the door of the XXXX XXXX became unhinged, preventing the door to close, thus deeming the oven INOPERABLE per the Manufacturer. 
XX/XX/2020 The merchant was immediately contacted and advised that both appliances were shown to have manufacturer defects prior to their use. The merchant and a XXXX representative refused to return and refund the appliances ; stating, repairs are performed on manufacturer defective appliances based on XXXX warranty. 
XX/XX/2020 I contacted XXXX XXXX to request the charge amount of {$1300.00} be placed under dispute due to the merchants refusal to return & refund the defective appliances received. It was stated that the company would suspend transaction pending investigation 8 to 12 weeks. I also contacted Citi Brand Source to request the charge amount of {$1300.00} be placed under dispute due to the merchants refusal to return & refund the defective appliances received. It was stated that the company would open a dispute which will take 6 weeks. 
XX/XX/2020 Follow up contact was made to Citi Brand Source in which the Dispute Dept rep stated the investigation would take 30 days, but ultimately it was up to the store whether they would accept return & refund appliances. 
XX/XX/2020 Correspondence received from Citi Retail Services stating their investigation determined I would be responsible for the disputed charges. However, the dispute would be reopened, provided supporting documentation was received prior to XX/XX/2020. 
XX/XX/2020 I contacted Citi Retail Services and discussed where/how to send the supporting documentation. The customer service rep provided multiple fax numbers and/or mailing address. XX/XX/2020 Per the customer service rep, the Dispute would be reopened as the submitted 27 faxed pages of additional documentation and the same 27 pages of supporting documents was received via USPS to the Retail Services. 
XX/XX/2020 Upon receipt of an account billing showing payment due XX/XX/XXXX, I contacted Citi Brand Source and spoke to a Dispute Dept rep who confirmed their receipt of both the faxed 27-page documents and the USPS receipt of the same documents. The rep advised the billing was auto-generated and the Dispute was in fact reopened. 
XX/XX/2020 A follow up contact to Citi Brand Source for status resulted in a conversation with the Dispute Dept Supervisor, stating the investigation was closed on XX/XX/2020 because of the merchants warranty. After further discussion, the supervisor agreed the dispute would be reopened and reassessed based on the recently submitted supporting documents received XX/XX/2020. 
XX/XX/2020 A follow up contact to Citi Brand Source for status resulted in a conversation with a Dispute Dept rep who stated the Dispute is closed. I requested & spoke to a department manager who stated the appliances are under warranty. After further discussion, the supervisor agreed the dispute would be reopened. I asked for a letter stating the same. The manager agreed ; however, no letter has ever been received. 
XX/XX/2020 Received Citi Brand Sources account billing showing payment due XX/XX/2020, past due {$0.00}, minimum payment due {$28.00}. 
XX/XX/2020 Received a collection call from Citi Brand Source account billing. I asked for the Dispute Dept and was told the dispute was closed. I asked for a written document stating that the dispute was closed and the reason for the closure. I re-contacted this credit card issuer up with another call to the Dispute Dept and spoke to a manager/supervisor who agreed the dispute would be escalated for further processing. 
XX/XX/2020 Received a collection call from Citi Brand Source. I immediately requested the Dispute Dept. The dispute rep stated I would need to work with the merchant to resolve the dispute. It was further stated by the rep, their records do not reflect two appliances only 1 a refrigerator. I explained the bill of sale purchase was for 2 appliances which included a cooking range. The rep stated, There is nothing more they would do on the account, the dispute is closed and they can not force the merchant to return the appliances. I requested a letter stating the closure of the dispute and reason. The rep stated, that would not be done. 
XX/XX/2020 It must be noted at this juncture, that XXXX XXXX issued its investigative findings of closure and issued a credit for the balance amount of {$1300.00}, stating XXXX XXXX XXXX has not yet provided the necessary information. '' By contrast, Citi Brand Source continued to blunder its way through a feigned dispute investigation resulting in my initiating over 21 separate phone calls, at least 4 requests to reopen their premature closures, while additionally providing numerous supporting documents regarding the manufacturer defected appliances. 
XX/XX/2020 I sent a follow up email to Citi Brand Source regarding disputed charges investigated by a card issuer are required by law to issue a written advisement within 30-90 days and the reason for the decision. 
XX/XX/2020 Received alerts from ( all ) three Credit Bureaus, in which Citi Brand Sources submitted a negative 30-days XXXX delinquency account billing. 
XX/XX/2020 I filed disputes will all three Credit Bureaus XXXX, XXXX XXXX, XXXX 
XX/XX/2020 Received correspondence via US mail from Citi Brand Source advising their credit line was being lowered on the issued credit card from {$5000.00} t0 {$1400.00} due to my Credit Score as of XX/XX/2020 of XXXX Credit scores range from low of XXXX to a high of XXXX. 
XX/XX/2020 Received billing via US mail from Citi Brand Source advising the account 's Previous Balance - {$1300.00} ; New Balance - {$1300.00} ; Past Due Amount - {$70.00} ; Min Payment Due - {$120.00} ; Payment Due Date - XX/XX/2020 ; Fees Charged + {$41.00}.