Bad purchase service

Good day, I purchased a back pack from Mr price cape gate shopping centre about 1-2months ago unfortunelly I do not have the reciept. They checked on my account past reciepts and could not find anything, I explained to the cashier/supervisor that I only purchase with my account never cash and she became very agrovative and rude. As if I was lying that I made the purchase on my account, never the less I wanted to exchange my bag as it tore by the top of the handle within 1-2months time. In any case I could not do that because they couldn't get the reciept and said they cannot do the exchange. What makes me more upset they weren't very helpful and said without a reciept they cannot help me. Funny enough they cannot find my reciept from my account. To top it off I wanted to exchange a charging cable and had a reciept but I couldn't change because I wasnt within the 30day period but note the cable is faulty and yet they still didnt want to assist me. Honestly this is bad service completely. Now I need to keep a bag and charging cable that is not useful.