Safair service stinks

How is this possible. I paid for my return flight via Pick n Pay flew to Lanseria on the 4 May and when I want to return to Ct my booking was cancelled because of non payment. I flew on this booking and payment. Now Safair tells me I must sort it out with their third party PnP as if I made a mistake. Safair is more concerned about profits and filling their seats than to provide customer service and care. The consultant tells me via their wapp service I must sort it out with their 3rd party. They have an STA agreement with them not me. I feel disgusted in this type of service.