Bad customer service

I was at Identity store in Randburg today for an exchange, I did not have an original receipt as I forgot it back home in springs, however I asked that they email me the receipt so I had a printout. The store manager refused to assist insisting that I should provide an original copy “reason being I would need to write the details at the back of the slip (her explanation)”. Even though I showed and explained to her that the return will expire on Saturday but she didn’t take it.