Refuse to accept payment

I went to Dion wired in Greenstone. I bought a washing machine. I then paid using my bank card. The bank has confirmed that a payment of R4 000 was paid to Dion. Dion now has taken me from post to pillar to pillar to post about this matter and say they did not receive this money of which it reflects on my statement that it was paid. So dissatisfied with the service and this whole incident as they have taken long to even respond to me.