belittled#absolutley appauled and disgusted

On the 25/01 my mum purchased some toiletries as well as a few items for my son totalling R1700+ afew days ago I realised she bought afew wrong items, so I went to hillcrest corner to refund them. When I got to the till a woman named sizwa 1st questioned whether the probiotic was purchased there or if its even sold in the store(its on the till slip)she then called someone to 1st check if the seal of the bottle was broken when told it was still sealed she still insisted that he put the bottle up to the lid to see if had been tampered with. So after having my integrity questioned considering I have gone back instore a few times to pay for items that were not rung up. I just wanted my money back and not do an exchange. I then got told its been more then 7days so I can only get a voucher yet the till slip states items refunded in 10working days qualify for a refund. I then purchased something this same woman came to authorise the transaction and told the cashier to not give me change in money but as a voucher again! As though it was not my money initially spent!! I have never been so disgusted and embarrassed and belittled as I spend thousands a month there and get treated like this!