Uber Eats Stole My Uber Cash

My Uber Eats account got banned for “irregular activities” and “misuse” which are “against the terms and conditions”. I am not sure what I did wrong — this happened after I added my Amex Gold card (which gave me $10 Uber Cash) and $100 worth of gift cards (bought at a discount from Costco). Nothing went wrong with my orders in the last couple of months.

The customer service does not help at all and is unwilling to tell me what I did wrong, or re-activate my account. I alerted them I still have Uber Cash in the account, but they repeatedly said that the Uber Cash is originating from gift cards, and that these are non-refundable.

Do I have any legal standing to demand a refund of the Uber Cash, which comes from gift cards?