Issue with stock online

Ordered a pair of shoes (***6) that were on sale (R1678.95) on Totalsports website on the 30th of June. I noticed the delivery status stayed on “processing” for a couple of days; I then received an email on the Wednesday (3rd of July) saying my order was cancelled due to a lack of stock. I then went back on their site and saw that I could still place an order for the same shoe in my size therefore meaning there was still stock online. I proceeded to call the customer service to enquire why my order was cancelled when there appears to be stock online still. The lady I spoke to told me that the reason for that is due to people making returns or cancelling their order and she suggested that I repurchase the shoes online. I waited a day as I was hesitant due to the concern of the same stock issue happening again and that my previous orders refund would only come through in 7 days. I then REpurchased the shoes on the 4th of July and the next day I noticed that the delivery was still in “processing”; with a hunch that the same stock issue occurred AGAIN I phoned the customer service to find out that it indeed was the same issue. The gentleman that I spoke to then apologized for the inconvenience and told me that there was one pair in my size at a Totalsports near me and suggested that I call and go purchase them there. I am now sitting with an outstanding refund balance of R3357,90 and now have to make my way to another store to pay ANOTHER R1678,95. I would not be making the effort to repurchase for the 3rd time if it wasn’t at such a good price. They really need to sort out their stock issue and I certainly will not be purchasing off their website again.