Citibank Credit Card Complaint

Citibank Credit card department,

Billing disputes Pennsylvania

My bloomingdales closed my account after I mad the payment and the account was still open, and now there saying that I have balance thats due. This is not correct because I made full payment and brought the account to a zero balance. I have spoken with them and they still arent trying to assist me but instead keep refering me to the collections agency thats now handling the bill, my account should not be in collection agency status because it shouldnt have a balance due ... ..