Product: Credit card or prepaid card

I have had this card for many years and used it frequently. I have both balance transfers at XXXX % interest and purchases. I understand that if I have balance transfers and other promotional balances that purchases won't have a grace period and will have interest. The issue is that multiple times Chase applied extra payment amounts beyond the minimum due to my promotional balances due months later rather than current purchases. In doing so they deprived me of the promotional XXXX % interest for the amount of time advertised and charged me interest on purchases that should have been paid off. Chase 's monthly statements make it very difficult to figure out what purchase amounts to pay to avoid interest. ( Their statement about " interest saving balance '' includes EVERYTHING even promo offers, so make NO sense ). My XX/XX/XXXX statement showed that my " Purchases, balance subject to interest '' was {$2600.00}. My XX/XX/XXXX statement showed that I had {$2400.00} in new purchases and had paid {$4400.00}, far more than the {$330.00} minimum payment due. I expected {$4000.00} to be applied to my purchases. Instead, Chase applied approximately {$1000.00} to XXXX % and other no interest promos not due for many months. ( It is impossible to figure out exactly how much because their statements are so unclear. ) Although my next minimum due was only {$330.00}, I paid {$1800.00} on XX/XX/XXXX, again in attempts to pay off purchases. When I received my XX/XX/XXXX statement, it again showed my extra payments going towards promos not due for four or more months instead of towards the {$2900.00} " balance subject to interest. '' I paid {$800.00} on XX/XX/XXXX, {$2100.00} on XXXX, and {$700.00} on XX/XX/XXXX which should have paid off ANY purchases. NOPE, on my XX/XX/XXXX statement CHASE showed payments of {$3600.00}, purchases of {$1200.00}, and " balance subject to interest '' of {$1100.00}, again applying at least {$700.00} of my extra payments to promos not due until XXXX. The XX/XX/XXXX statement shows that my payments of {$1300.00} ( well in excess of the {$260.00} minimum ) were applied to XXXX % promos not due until XXXX, instead of to current purchases. My XX/XX/XXXX statement shows {$3500.00} in payments and purchases of {$1800.00}, and again, applies my excess payments to XXXX % promo balances due in XXXX, rather than current purchases. My XX/XX/XXXX statement shows payments of {$1800.00} and purchases of {$1200.00}, with more than {$700.00} going to XXXX % promos due in XXXX, but still having a " purchase, balance subject to interest of XXXX!. After this abuse I stopped using the card, but no matter what I pay, Chase continues to apply my payments in excess of the minimum to XXXX % promos due far in the future and not to interest bearing charges. Realizing that I had paid my " purchases '' MANY TIMES OVER and no matter what I did, Chase would not let me pay them off, In XXXX I paid only slightly more than the minimum due plus interest charged the previous month. My XX/XX/XXXX statement shows {$260.00} paid, one purchase of {$9.00}, " Purchases, balance subject to interest '' of {$1500.00}! I have called Chase several times about this issue and each time get vague excuses and am told an amount to pay that will pay off my purchases. This week I was told that if I paid {$1500.00} my purchases will be paid off. I have done so but know they will not pay them off and will instead apply it to XXXX % balances due way in the future. In this week 's phone call I requested a detailed statement explaining where all my payments for the last 6 months went. I was told they could only provide one for the last 3 months but would send me that letter. Today I received a letter in my Chase inbox, which says only that I can find details of how payments are applied in my Cardmember agreement! My point is that they are NOT applying payments as per the member agreement and are RIPPING ME OFF!