Comenity charged interest on ending 0% BT promotion even though I paid in full

[Anonymous]

I have the BJ's Mastercard from Comenity. They have been very generous with 0% fee/0% interest balance transfer offers. I had used one last January which was ending on 6/30, and just took advantage of a new one that is 0% thru 12/20. I owed $5234 on the old plan so I made sure that I paid it by 6/30, then made the minimum payment on the new plan ($238) by the statement closing date of 7/10. When I got my July statement, I found a finance charge of 50c (minimum based on 46c actual) charged on the old plan with an average daily balance of around $111 after the plan ended. I emailed them to complain and they told me the following.

I'll be happy to assist you. Your payments are divided between the 
balance transfer and the revolving balance on the account. A portion of 
the minimum due will pay 1% of the balance transfer amount. If the 
payment is for more than the minimum due, the remainder will go towards 
the revolving balance as that balance is subject to finance charges. To 
avoid finance charges from being billed to the account, your payment 
must be for the total revolving balance and at least 1% of the balance 
transfer amount.

If you do not pay your plan 175-00001 balance of $18,262.00 by Dec 31, 
2020 interest will be begin to be charged on any balance remaining. If 
your plan 175-00001 is currently being assessed interest at a low APR, 
your rate will increase as of Dec 31, 2020 on any remaining balance. 

It seems like they took a piece of my initial $5234 payment and applied it to the new plan minimum payment, even though it had a later due and plan expiration date. I guess I should have paid both before 3 but it seems really stupid that they credited it this way (not to mention refusing to refund the 50c when I complained about it). On the other hand, I've done very well getting free use of their money so I should probably just pay the 50c. Amusingly, I've never actually used the card for a purchase, just the BT's.

BTW I just emailed them asking how I ensure that my payment this month goes to pay the full 50c due on the old plan given that it seems they would otherwise pro-rate the payment.

[NRB525]

Congrats on all the 0% offers.  

You can ensure the $0.50 is paid by paying the minimum payment, plus an extra $10 to ensure that covers the $0.50.  Most of the time. 

It is possible you are now on a “50-cent train”.  Each moth the 50c appears, just after statement cut, it may trigger another 50c charge for the new month, which only appears on the next statement print. When coming off one of these situations, I always tried to jump on the minimum payment, plus the necessary extra to kill the minimum interest, within a day or two of the statement. Usually that worked, but one time I got on a $1.50 minimum recurring interest with USBank that I could not kill. Had to call them after about 3 months of this to ask the CSR to throttle the pest for me, which he did.