Barclays PLC Credit Card Complaint

Barclays PLC Credit card department,

APR or interest rate California

Hi I need to lodge a complaint against Barclays credit card. I paid my deferred remaining balance of $75.00 on - - but on the - - statement, they charged me for deferred interest charges in the amount of $220.00. They said they reserve the right how to apply payments. I paid $100.00 that covered the deferred remaining balance of $75.00 on - - which was the due date. I can not afford to incur additional interest of $220.00 as I paid everything related to that balance by the promotional time period. I think it is just unfair on my part that the bank is taking advantage of it and asking me to pay additional $220.00 and that is why I am reaching out to you. The minimum payment due was $39.00. Thank you.