Poor service and stock not received

I placed an order at Incredible connection Tygervalley branch. My products was in stock at that specific brach at the time I placed an order. A day later my sister placed the same order, we paid through pay flex and she received her order before mine. We decided to go into store to see what the hold up was and they told us that the product is out of stock and he, the manager has no idea when the stock will arrive. we questioned the fact that the second order was delivered before our and his response was it is either the system at faulty or they have not received our payment but we used the same payment method. The manager was needless to say pretty useless, did not apologise and kept on blaming it on the system. We spoke to head office for about an hour, they tracked our orders including the one that was collected and they admitted that it was the branch that is to be blamed. We phoned the branch spoke to the same so called manager and he still did not take blame and claimed that the head office could not make that accusation as they are not in store, yet he still refuse to take responsibility. We asked when we can expect our stock and no surprise he is still unable to tell us. This is absolutely UNACCEPTABLE service especially from the "manager". This is very upsetting as I am now delayed with my orders and losing clients just because the manager can not do his job properly! There are so many jobless people that WANTS to work, it's time for the manager to step up and appreciate his job.