Product: Credit card

I purchased a new iphone and apple care on XX/XX/XXXX. Apple Card through Goldman Sachs had sent an offer stating that if you opened the Apple Card by XX/XX/XXXX and made a purchase of {$500.00} or more within 60days of account opening then you would get {$100.00}. I opened the Apple Card ( Goldman Sachs ) on XX/XX/XXXXXXXX  and purchased the iphone and apple card on XX/XX/XXXX spending over the {$500.00} requirement. The first thing that happened was that the 0 % interest monthly payments did not get setup with the online purchase. So I called Goldman Sacks and spoke to XXXX on XX/XX/XXXX to get the monthly installments set up, XXXX set them up on the test amount that Apple sends to the card and she did not set them up on the final purchase/ correct amount. So when I noticed there were not two charges ( test amount & final purchase amount ), plus the monthly installment plan - I called and spoke to XXXX on XX/XX/XXXX and then supervisor XXXX- they had to write up a ticket to have someone on the tech team fix it. I spoke to XXXX on XX/XX/XXXX, the day before picking up the phone, and they were still waiting on someone to fix the charges and installment plan, but assured me I could pick up my phone and there would be no issue working it out. I also mentioned to her that I did not receive the {$100.00} cash back as per the offer, and only received 3 % cash back. She said that I would have to open a ticket, but they need to get the other issue solved first. I filed an inquiry for my {$100.00} cash back on XX/XX/XXXX. On XX/XX/XXXX, they emailed me to send additional details. I sent them a screenshot of the offer. On XX/XX/XXXX, they sent an email asking me to contact them. When I did, the person had to send in another inquiry because the other one had been closed saying they didn't receive more information. On XX/XX/XXXX, they emailed again asking for more details/ proof of the offer. Again I sent the screenshot, but then was told that I needed a copy of the email with the offer. I explained that its been over a month and that email was already deleted and I had no access to it, but its why I took a screen shot of the link/website with the offer that the email led me to. Goldman Sachs did not want to honor their {$100.00} cash back offer, and because everything else that had gone wrong since opening this card. I chose to return the iphone and apple care. I spoke to XXXX on XX/XX/XXXX, and was informed that the refund was there, but in order to have it credited immediately to the monthly installment plan, I would need to close the account/ card. I did that, but then he sent me to a supervisor, XXXX, because the refund amount wasn't being immediately credited to the monthly installment plan, and that he still saw the monthly installment plan active. XXXX then told me that the account is closed, but that XXXX misspoke and that the refunded amount would be credited monthly to the installment plan. She said she would submit a ticket to the back office to make a case to have the refunded balance credited to the installment plan immediately, since it covers the entire amount of the installment plan balance, plus a credit of {$6.00}. I missed a call on XX/XX/XXXX, so I called back in and spoke to a supervisor XXXX, who told me that the case was closed, and the monthly installment plan for 2 yrs would remain. I told him that this makes no sense, that Goldman Sachs would not be making any money on this. That the account is closed, and that the refunded balance covers the entire balance of the installment plan, so they have no way to make any interest. Also that I have really good credit and I didn't want it effected because it looks like there is a balance sitting on a closed credit card for 2 years. He escalated it to the advocacy team, to again request that the refunded balance be credited to the installment plan immediately, and not monthly. XXXX called me on XX/XX/XXXX to let me know they were denying my request and keeping the monthly installment plan.