Worst Customer Service!

On Sunday 25th November I bought underwear at Mr Price in Access park, I accidentally took the wrong size the package was not opened I just took it home and realized it was wrong, kept the underwear in the Mr Price packet until I was able to get to a store I know that stores have a no return policy for underwear but this was not even opened it was still in it's original package the same way I bought it was the same way I wanted to return it. On Saturday 01st December I went to Mr Price in Kenilworth Centre, the guy at the door took the packet put the sellotape and asked me if I have the receipt I said yes he then asked for me to write my name on the packet which I did. I went to get the correct size stood in a long line because the cashiers were all busy doing who know what eventually when I got to the till I told the lady that I would like to exchange the items bought, she went to fetch my packet then came back and said oh we do not exchange underwear, while she was busy with me she was busy talking to the lady standing next to me that was also asking her questions, I said to her she can see that I didn't even open the packet nothing she refused said I must go to her colleague, I went there she said to me that we do not exchange and at the back of the slip it is written there. I said to her but you can see that I did not even open the damn thing what must I do with underwear that does not fit? I am suppose to bring the person with me everytime I buy something she says there is nothing she can do she calls the manager to come and tell me the same ****. Not one person was willing to help me, had that been Woolworths I wouldnt even have needed to go to the next cashier they would have probably just called for authorization. The manager at Mr Price tells me that they can refund me, so I said now refund me so that I can purchase the correct size she says oh no not here we can't help you, you need to go back to Access Park, bull****!!!!! I went to Access Park Sunday 02nd December, firstly there was no one at the door to take the packet, secondly I went to stand in the line, got to the Cashier she tells me the same story that Kenilworth Centre told me that the policy is at the back of slip, I said to her but Kenilworth Centre said I should come back here to get a refund and then I can purchase the correct size the girl says no we cant do that and refers me back to the slip, she then asks the manager next to her that was not even interested in looking or actually willing to help. That was by far the worst customer service that I have ever received from retail store. I now will be traveling with items that do not fit all because Mr Price was not willing to help!!