Mr Price Sport not honouring what is advertised

I was trying to purchase a promo they have online for a diving set that is selling for R9.99. I'm currently busy with disadvantaged youth and busy with a water safety programme that we will be doing in the holidays and after purchasing safety equipment and other water floating devices, we were wanting to secure some masks and flippers for the kids and that's when we came across the ad online thinking it was a God send as we funding the project from our own pockets and need 20 of these sets as a start due to our linited budget. That is where this nightmare begins, after numerous calls for assistance as the website keeps timing out when trying to make the purchase, I ws pro.ised someone would get back to me after numerous back and forth calls. When checking now on the website which I was constantly checking, a week later it's showing out of stock. This is totally unacceptable. I can believe that a reputable company like this can just leave their customer's high and dry and not even get back to me or let alone assisting in remedying this situation. Can a Senior Person please contact me as this is not what I was accustomed to as a long standing customer. Can someone please assist.