Chase has reformed themselves somewhat. Considering they are rats to deal with when it came to credit cards (I no longer have one with them by choice).
I had a card with FirstUSA and BankOne both of which were acquired by Chase in the early to mid 2000s. Those rats switched the accounts to multi balance accounts. Using the SAME CARD they would segregate purchases, cash advances, debt transfers, etc. Then they would apply your payments to the LOWEST interest rate segment FIRST and RECAPITALIZED (added back to the card as unpaid interest) the amounts not paid by your payment.
In detail:
If you had a $5000 balance of which $3000 was a balance transfer @ 5%, purchases of $1500 @18% and $500 cash advance at 21%, your payments were applied to the lowest rate first (which is usually the highest balance). If your payment wasnt for $3000 in one payment (nobody usually does that), then the other balances not only contiuned to earn higher rates, but they considered the interest UNPAID on those amounts and increased your credit card balance by those amounts! Then they would charge interest in THOSE SEPARATE CATAGORIES at the higher rates SO YOU NEVER PAID THEM OFF!
In effect, your 18% card would be earning them upwards of 36%+ and growing! Your new balances would now be $1500+40+42+48+50 and $500+15+18+20, etc. You could never pay them off because they kept increasing the damn balance underneath you and would not let you pay them unless you practically paid off the entire $5000 at once!
CHASE was nothing but an evil POS and refused to do anything for me other than to ignore, argue, demand, deny, play stupid, transfer around and act like TOTAL RATS when it came to this matter. That was over the phone, in person and in writing via certified mail.
NEVER AGAIN.
edit: This method was called "double cycling" and was outlawed back in 2009. Leave it to CHASE to be the evil POS that led the way in this arena.