Synchrony Financial Credit Card Complaint

Synchrony Financial Credit card department,

Late fee New York

I use a payment service to pay my bills ... Always have with pretty much no issues that could n't be resolved. I scheduled my ( - ) payment for my Walmart card as I always do but apparently the payment was sent to Walmart a day late. I did n't realize that I was assessed ANOTHER late fee until I got ready to pay my new bill ( - ) that came out. I went ahead and paid my bill ON TIME minus the late fee while disputing the fee with Walmart. After some back and forth they finally reversed the fee but at the same time assessed me ANOTHER late fee because I did n't pay they previous full amount. I explained to them that I was not obligated to pay an amount that was in dispute and they followed up with they ca n't fix it and that I have to pay the full amount. I find that not to be true and it to be unfair because of one discrepancy. Now I 'm getting collection calls for basically another late fee that I am refusing to pay. I have asked them to fix this situation to no avail.