give me a full refund

on the 28/11/2017 we bought a tv at game store in jabulani mall on the 9 on mach the tv gave us problems and we took it back for repairs and we waited for two months and they called us and told us that they said they will charge us a certain amount to fix the TV and we told them that we have bought an extended warranty for TV and we back to submit the warranty documents on the 5 of june 2019 and then after two weeks the send us a massage that the TV was fixed only to find out that the TV was worse than before and we took it back and they told us to wait for two months on the 25 of September 2019 we called them and they told us to come with the documents and accessories of the TV for a full refund but on the 26 of September 2019 they denied to give a full refund