Bad service with cash crusaders

I bought a brand new TV at Cash crusaders heidedal in Bloemfontein for my Mom 3 weeks ago,now the TV switches its self off now and then and because I can't find my receipt I lost it i called they dont want to help,what kind of a service is that,and the copy you guys kept why can't you help your clients with it,the transaction does show on my statement why can you also use that?because I lost a receipt I must now stay with a malfunctioning TV worth R4000 just like that,that's not customer you can do better guys