Identity Northgate terrible experience

I’ve bought two garments at Identity Northgate last month. I’ve returned both garments back at the store on different days. I was given the till slips on both occasions to state that the money was deducted from the account. I then realised I had a “R0” balance initially when I bought the garments so if I returned both I should not be owing any money. The total on my invoice did not reflect that. Queried this with the gentleman who assisted me with both returns. It was a Monday. He assured me he would fix the mess and call me on Tuesday after 4. I ended up calling him on Tuesday afternoon just to be told he is very busy and will call me back on Wednesday afternoon. On Wednesday afternoon a get a text from the company saying I should pay my account. The full amount reflects as to the garments that were returned that I need to pay for after returning them. I still haven’t heard from identity northgate regarding their mess up. I am suppose to pay my instalment before the 3rd of January on garments that I don’t even have.