Bad service from complaints department

I once had an account with the store years back and i was out of a job and couldn't continue to pay, found a job and app**** for a consolidation with FNB bank in 2014 October and they settled the account for mr to the value of R4,374.60. since 2015 i have been struggling to get the store to assist to allocate the payment to date. I am not sure what they want me to do as this amount was paid into their absa bank account then, i even gave them the proof of payment given to me by FNB bank.