Pathetic Customer Service at Builders - Riverhorse Valley Durban!!!

I made a purchase for my business on Jun 4th - with one item to be collected the next day as they didnt have it in store. I received a till slip and usually i receive an emailed copy of the invoice for vat purposes but this time i didn't. I sent an email on the 14 Jun requesting this. no response. I sent follow up mail on 15th Jun. no response. Sent another follow up mail on the 19th June. No response so i called in. the call Centre said thy would come back to me before lunch. no response. I then sent another mail that day at 14h00 to which the Customer service agent sent an email asking for time, date, details, amount and inv number of purchase. This frustrated me because as a business who makes frequent purchased from this store i have an account number - shouldn't this allow them to pull out invoices?! Nevertheless i responded to her with some of the details i had. No response thereafter. I made a few calls yesterday to which they tell me that there is no purchase reflecting on their side. HOW does this happen, and might i say that I have a slip as well as an account number with them. I then ask to speak to relevant personnel at the Riverhorse valley branch. I have left messages for them to call me back but They have not had the decency of coming back to me and i have done multiple calls to the branch to try and speak to them! This is absolutely pathetic customer service and after sales service from you guys as a WHOLE!!! to say im frustrated is an understatement because i don't have time to chase up on an invoice for a purchase already made!!! this should be damn accessible with me gibing you my account number! Im still waiting on a response or a call to get the invoice! I cannot believe that the lack of response has been this appalling! TERRIBLE SERVICE in my opinion and il definitely be thinking twice about making purchases from you guys and would rather go to your competitors!