Bad service

I bought a tv stand yesterday, on Monday i came to collect it,i found that the stand i bought was a demo therefore it is in bad condition, for me to buy it as brand new i thought its unfair ,i asked for a refund

They want bank statements plus id but i had a proof of purchase, they also said i will get the cash back probably next year ,i need cash back (refund) immediately because i need to go and buy onother one somewhere else.