Citibank Consumer Loan Complaint

Citibank Consumer Loan department,

Installment loan Managing the loan or lease New York

The financial institution I am dealing with, Citibank, has missapplied funds which I sent in a timely manner to pay this loan and I can not seem to get any help removing late charges I was charged due to their mistake. I have sent payment which was supposed to be credited to this account and was mistakenly credited to an old, closed account which Citibank could not transfer to the right account. As soon as I was made aware of their mistake I requested a refund and sent another payment which was credited correctly, however, there were 2 times this happened and I was charged late fees I would like refunded as I was at no fault in this matter. I have sent letters and made numerous calls without any luck.