Terrible customer service!!

Yesterday afternoon at approximately 17:30 I purchased items from SPAR Hunters Retreat in Port Elizabeth. Upon arrival at home the one item was defective, and I accordingly returned to the store today to have the item exchanged. Important to note that the patron did not provide me with a slip in respect of my purchases yesterday. Needless to say, SPAR (Jay) advised me today that they cannot exchange the defective item (on account or not having a slip despite the obvious ommission to provide me with one to begin with) and that the slip in respect of my purchases could not be reprinted as the employee authorised to do so had allegedly left for the day, and have been advised to contact their store on Monday. I showed the SPAR employee my bank statement and sms received in respect of my purchase and was still showed away. I visit that respective store almost daily and purchase from them frequently as they are ideally located close to my home, but have no intention of ever purchasing from the store after my experience today. Despite the obvious inconvenience, i fully intend to attend the store on Monday for a FULL REFUND. Not a single cent more will be spent there irrespective of the distance i will have to undoubtedly travel to the next available store. The customer service is absolutely atrocious!