Poor service and advertising

I was waiting till midnight for the Black Friday deal on the PS5 for the deal for the first 10 customers that will receive a discount which will be app**** on checkout. I received the discount and when I went to make payment the system refused to allow me saying to please try again. I kept trying till 2.30am but still received the same error. Later in the day I spoke to a person in customer service who told me that the 10 customers who successfully processed their order received the discount, however that’s not what was advertised, it’s said the first 10 customers to apply the code will receive it, it said nothing about making payment. After asking to speak to the manager, she advised the same. I asked her to speak to her manager and she said she would get him to call me back which up till now hasn’t. I then called into head office and spoke to another representative in customer care who said she was going to investigate the issue. She asked me to send through the proof I had which I did, sent screenshots showing what time I tried paying for my order 12.04am. She then said she would get back to me as the CEO of Massmart is investigating this. She emails me in the evening saying the same thing that was said to me previously, that the discount was for the first 10 customers that processed payment on the order. She also stated on her email that the 10th customer processed their order at 12.30am, when I was trying to process at 12.04 which it didn’t allow me. They first said their system was down and back up again. I asked for her supervisors info but got no response. I then called head office again and asked for her managers details which I spoke to him yesterday who was the customer care manager. He advised me that the system was down from midnight to 12.39am, which I then asked if the system was down how did the 10 customers process their orders all by 12.30am and I wasn’t allowed to. He said he would double check the time stamps and get back to me today which he did, only to tell me now that the system was down only for a very short while and was working again and also confirmed the times the 10 people processed their orders for this promotion with the last one being at 12.30am, so again I asked if the system was working how come I couldn’t process my order which he had no answer too. During this time which I was trying to process the order my wife tried processing another item which worked perfectly fine. Until now the item is still in my cart at the discounted price but still unable to process payment. Other people who tried late to process the order for the PS5 deal, the item was removed from their cart saying it was no longer available as it was sold out and they was too late however mine is still in my cart. Game is refusing to honour the deal now as they are saying they already have the 10 customers which is wrong as the system error was on their side and need to take accountability for it. The evidence I sent through to them clearly shows that I was actually one of the first of the 10 customers for the deal. I had to open a case with the ombudsman and their ethics department due to this.