Malicious attempts to make money off dead accounts

Don’t ever make a mistake of leaving an inactive account with Standard Bank , I’m learning the hard way, in 2015 I had left my account active but not transactional for over 6 months, the next thing I know a collection company calls me on behalf of them stating I owe the R6900 incured on the account. Tried resolving this but I’m told there is nothing I can do except pay that money to resolve this issue! ****en Rippers!! I will never ever do business with them again