Product: Credit card or prepaid card

To whom it may concern, On XXXX, XX/XX/XXXX I purchased a gift for my boyfriend from a seller based in XXXX totaling {$500.00}. 
I used XXXX to check out so that I would have an additional form of protection in case something went wrong. 
When checking out the estimated delivery was said to be in 15-20 days. 
It was shipped out the next day. I saw that the estimated delivery was earlier than anticipated and called XXXX on XX/XX/XXXX at XXXX so that they can place my item on a vacation hold while I was away to visit my family out of state. 
The gentleman I spoke to assured me that I had nothing to worry about and that my item will be held at the local XXXX facility in XXXX, TX for pick up whenever I will return. I called XXXX again on XX/XX/XXXX to make sure that my item was being held at their location and the lady I spoke to confirmed that they had my item and that I will be able to pick up at my convenience. 
Two days later a member of my household tested positive for XXXX and we all had to quarantine for 10 days as well as reschedule our flight back to a later date. 
Upon returning to Texas, the next morning I drove 40 minutes to my local XXXX office and the lady at the office told me that they don't know where the package is and to come back in another 2 hours while they locate it. When I came back she simply told me they don't have it. 
They claim that the package was delivered to my door anyway. 
However there was no package anywhere to be found when we arrived. My neighbors and the building 's management office also confirm they haven't seen it. I called XXXX again and now they already claimed that I never asked for a vacation hold. 
I tried to resolve with the seller but they kept saying that the package says delivered and that this isn't their problem anymore. I explained to Discover that it isn't right for the seller to send such an expensive item without insuring it or at least requesting signature on delivery and offering absolutely no customer service. When I asked XXXX about this issue again they said that they can not talk to me as they have a contract with the seller and they are the ones who should contact them. However the seller continued to do nothing. 
I opened a case with XXXX and Discover but XXXX automatically closed my case because according to them I was not able to have multiple cases open, which I wasn't aware of. When I called them they said that they're investigating but ultimately Discover will get to decide what the outcome will be. 
I tried to explain this whole situation in details to Discover and attached all the evidence. At first within few days they said the case was closed in my favor and I breathed a sigh of relief. 
However, several weeks later Discover suddenly reopened the case and without any explanation gave the seller back my money. I called them to ask what happened but all they said is that they're investigating and that I will get the money back shortly on my account. 
I asked if there is any additional evidence they needed and they informed me that everything was fine and that I should just be patient. I called again in another month to check the status and ask why I still didn't get the credit they promised me but again they informed that a credit will be posted to my account shortly, which never actually happened. 
After 3 months of waiting they ended up closing the case in favor of the seller without any explanation and XXXX automatically did the same. 
So in the end I never got my item, lost {$500.00}, wasted countless time and nerves on correcting someone else 's mistakes which I still unfortunately wasn't able to achieve. 
Please find attached below my receipt from the purchase, airline ticket, time and date of phone calls to XXXX from when I requested to put my package on a hold, messages from XXXX telling me that it is the seller 's responsibility to contact them about the lost package, my emails with the seller where they completely ignore the problem, Discover 's final resolution and a complaint against XXXX on XXXX XXXX XXXX that I opened where they eventually admitted that they didn't follow instructions but still refuse to reimburse me for the amount I lost. 
Please look into this and get back to me as soon as you can. 

Thanks, XXXX