POOR SERVICE DELIVERY

I purchased a COBY television from Cash Converters Mayville, Pretoria on 09/08/2017. On 08/11/2017 I noticed that the television had lines across the screen. I took the TV back to them but they could not replace it and rather sent it in for repairs. I was told that I need to wait 7 working days for the return thereof. I queried their guarantee policy that states REPAIR OR REPLACE OR REFUND. They insisted that it must be repaired and I am not entitled on the other options.