Worse customer service ever!

I bought two items using the online platform and when i returned one iteam to the Westgate store, they said they can't assist because i didnt have the invoice which was supposed to be sent to me by the online team. I left the item there with the store manager on the 30th May 2020 who then said she will get in contact with the online team so she can process the return and then phone me back once done. Today is the 23rd June almost a month later, the return is still not done and she hasnt phoned me back. This is absolutely ridiculous service and shows they don't care at all for their customers and in the meantime i am incurring interest on an item that should have reversed.