TCM Bank review: Refusal to reimburse fraudulent charge on my credit card

I have a Visa credit card through TCM Bank in tampa Florida. Address is PO Box 30495. Their Phone Number is [protected]. I've had the card for years and not had serious problems until this thing arose. In January I discovered several fraudulent charges on my bill. I immediately contacted the phone number on my card. They immediately cancelled my old card and provided me with a new one with a different number. There were four fraudulent charges from what appeared to be some sort of subscription; each of these was for less than $40 and each of those charges was refunded within the next few weeks. There was also a charge for $526.96 from The Goose Community in Clinton, Washington. (It's a grocery store). TCM has never refunded this. I have made many many many phone calls to them. There is a weird little runaround they do wherein one person tells me I need to talk to "your band", which is TCM, and when I demand the bank's phone number it turns out to be the same number as the "chargeback" company which purports to do the work. It is frustrating belief and I can feel my blood pressure rising as I write this. For the past couple of months they always tell me that the refund has been approved and that the reimbursement will be forthcoming shortly, but it never actually arrives. On April 2, they sent me a letter saying that they concluded that an error did occur in this case and that the letter serves as a notice of final resolution. I called them again, and told that this meant that I would receive a refund. But I didn't. That happened twice. My most recent conversation was with a person named Cynthia who told me firmly that "I can fix this for you!" that was on April 18, and it hasn't happened yet. Can you help me?