Product: Credit card or prepaid card

Purchases were made on XX/XX/XXXX, then returned in the store on XX/XX/XXXX, during this time they were doing returns differently than normal because of covid restrictions, I had to hold the items tags up for them to scan and then place them in a box and I was told they would email me the receipt for this return. I never received the credit for the returns, went back into the store on XX/XX/XXXX to speak with someone in person because when I called the stores customer service line they said that because it was a store purchase and return they could not help me. I spoke with a " manager '' named XXXX who was able to see in his system that the items had been returned and were not eligible for a return because it reflected in the system that they were already returned on XX/XX/XXXX. He said the sales audit team would have to do a little research and he would have them call me, he took down all my information. I never received a call, and when I called the store a couple weeks later they said XXXX no longer worked at that location and they referred me to their 800 number customer service. So I filed a claim with Synchrony Bank XX/XX/XXXX and provided them all these details. They said they conducted an investigation after several months and the merchant provided further proof so they would be re-adding the charges to my account. I called them in reference to this letter and asked to see what proof was provided by the merchant, they were not able to answer that for me and suggested I reopen the fraud claim. I did just that and provided the same details as before, after a few weeks I received a letter requesting via fax or mail more details in writing, I submitted these to the address within 2 days of receiving the letter, a few weeks passed and they closed the dispute because they did not receive my response, I called them back immediately and explained that I mailed those in as requested ( This was on XX/XX/XXXX ) they apologized said it was probably a mail issue and to please login to their online account and upload the letter I mailed in through their secure message center. I did that immediately and received a response thanking me for submitting those and they would be in touch. Then on XX/XX/XXXX through their online message center they sent a letter saying they had received additional documentation from the merchant to support the merchant in the claim and to please see attached. The attachments were not from the merchant they were the documents I had sent in for the dispute originally. The letter provided a number to call if I had any further questions. I tried to call this number, and it says because of covid they have limited staff and instead to call the number on the back of my card and then the call disconnects. I then called the number on the back of my card, they can not provide the documentation as they state they do not see any being sent in by the merchant and my only recourse is to continue to dispute the transactions. The merchant can not help me due to the length of time that has passed according to the stores, and the bank refuses to help advocate or assist me in trying to get further information from the merchant. I continually get disconnected when trying to speak to the fraud department at Synchrony, and recently had them close my account without verbal authorization.