Helzberg Diamonds Shops review: Credit card scam

I was sold the 12 month interest free card deal when I bought a ring for my wife on 9/15/2024 for 1956.43. As soon as I got the card, I set up autopay to cover the cost in 12 payments. The system set up the autopay date for the 28th of each month. Every payment arrived on time. I just got a fraudulent $560 interest charge from Helzberg's servicer, Comenity, added to my account because they say I wasn't paid in full by 9/15/2025. This would have been technically true, however, I actually paid it off in 11 payments because I increased my monthly payment amount in June. Nevertheless, they refuse to remove the $560 illegal charge. As of 9/15/2025 I had paid $1989.50. If you include the service fee of $39.12, you could argue that I am $6 short - so by the letter of the law maybe they could charge me the balloon interest fee - however the service charge did not post to my account until 10/2/2024 and by 10/2/2025 I had paid another $193, so I'm inside the window no matter what. This would be predatory and unethical behavior even if I hadn't paid it off in 11 months - their system set the autopay date outside of the time frame that would have fit 12 equal payments. This is evidenced by the fact that they still charged me the balloon payment even though I actually had paid it in full. Further to that point - when they sell people on zero interest if paid off in 12 months, they do not say "if you do not pay it off in 12 months you will owe the full 35% interest on the entire purchase. Not just your remaining balance." This is unethical false advertising.