JPMorgan Chase & Co. Credit Card Complaint

JPMorgan Chase & Co. Credit card department,

Billing statement Nebraska

I pay my Chase Sapphire Card in full, every month, without exception. At times, I end up paying a few days late due to travel/work. Because I pay in full, I call and ask at time of payment for a refund of any late fees/interest ( if any ), and they have 100 % of the time obliged ( for obvious reasons ). -/-/2016 this happened again, and I was told on the phone that the late fee/interest was waived and I paid the remaining balance in full. As it turned out, they only waived the late fee, so I in actuality did not pay in full, kicking off a series of monthly interest charges. This happened -/-/- and -/-/- as well as I was traveling for work/holidays over the due date. I again paid in full and called and they said the fees/interest were waived. It only now has come to my attention that the interest was never waived as told, which means my payment " in full '' was short an unknown interest payment, allowing them to rack up hundreds in interest fees ( that I thought were waived ) on purchases that were paid in full. When I called them, they said they could n't do anything, EVEN THOUGH THEY HAD TOLD ME FOR MONTHS that those fees had been waived ( and therefore I was paying in full ).