Charges on zero balance account

I have an account with Edgars for many years. In October 2020 I paid the balance outstanding and have not done any purchases since then. Today I received a call from debt collector saying that I am in arrears and I need to make payment. I did not receive a statement or sms or any form of communication stating there are charges on my account. My credit score is now compromised as I never let any of my accounts go in arrears. Why are there charges on my account without my consent and my not being aware of anything. In previous years if the account is paid up, there were never any charges. This is disgusting and I am extremely upset especially that my credit record is now tarnished. Why should I now close the account to avoid unnecessary charges?