VODACOM STORE ISSUES

I am a big supporter of Vodacom and their Black Friday deals. The latest issue is that i went online and i understand the stocks are limited. I placed an order the item is in my cart. I went to pay for it only to be told its unavailable... How is it possible that i was able to put it my cart if it was unavailable? There is no option to even query this matter. This isn't my first issue with the vodcom store. I had an issue when i bought something using vodabucks there was a system issue it took the bucks and issused the voucher after i left the store and they refused to refund the vodabucks.... i also placed an order with one their suppliers ebutler. In this occasion they didnt deliver the order items and despite a few complaints i never recieved a refund. My resolution is i want to pay for whats in my cart at the price i orginally picked it for. I would let everyone know that need to be careful when dealing with the vodacom store. There is no customer service and you only have a 50 percent chance of getting the item. If u do pay for it you may never get the item. And dont hold your breathe for a refund.