Synchrony Bank Credit Card Complaint

Synchrony Bank Credit card department,

Credit card protection / Debt protection California

I signed up for the Care Credit account I 'm -/-/-. They had a " promotional '' deal with low interest rates good for 18 months ; the rate thereafter would go into the high 20 's ( 26 % + ). The expiration for the low rate was -, whereupon an accrued amount of $3000.00 was added to my balance taking it from $ - to $ -. My understanding of how the rate increase would occur was that at the end of the promotion, my remaining balance would be charged interest at the non-promotional 26 % + rate. It was never explained otherwise to me.