Kulula not refunding my double payment.

I made a booking on 17 January 2019. Payed with credit card. Did not get confirmation and when I phoned was told payment was not received and I must do EFT which I did. Then discovered credit card payment went through. Was then promised it would be reversed within two days. Did not happen. Then I was told to fill in refund form which I did. I have proof that it was returned to them. After some weeks no response. Phoned again and was told they did not receive form. I then sent it again and confirmed with them that they received it. That was three weeks ago. Still no response. Would I be wrong to suspect that they are trying to wear me down and hope I will give up. FORGET it.