Have 5 days to return purchase , get respons

On Wednesday 27 January 2016 I purchased R3500.00 from their stand in Somerset Mall , Somerset West. The Friday night I have terrible pain in my legs and was very sick. I decided to give it back. did not use the items the next day I go back to them in Somerset MAll, they said I have to contact the the Costumer Care Department , at ***. I do that and talk to a lady Sarah, she said I have to send her a copy of the invoice, that I do, after a few days I have no respond, I call them again, she said they are busy with my case and will let me know. She then send me an email with the following words : On 3 FEB 2016 : \You may return your items purchased. Please email your banking details ones the item have been returned. ON 5 Feb 2016 I send a copy of the return invoice 4854 with my banking details, up till date they do not pay back my money. I contact them several time on ***, after lot of calls a man answer I said to him let Sarah contact me please, she did not respond, I send a lot of emails, no respond. Can you please help me to get back my money. "