Very disappointed

Wow.. i am stunned for words... I still have a months guarantee on my battery and Durban Battery in clairwood,teakwood road refuse to change it for me simply because i cant find my reciept... the date and invoice number is engraved on the battery as a standard procedure for battery guarantees but they still will not assist!!! have been dealing with them for years. My entire family and i but will never ever support them again...! Cannot believe this is how there customer service works...