Buffalo international logistics - horrible customer service

If you can avoid it - do not use buffalo logistics. If everything goes smoothly, they are decent and I used to not mind using them at all. But if you have a query or issue- they are absolutely useless. They owe me over R600 and refuse to refund me - and when I ask to speak to a manager they are always out of “office and will call me back” - spoiler they never call back. I ordered an international package and the following day received a request from buffalo to pay Vat and Duty - I paid the same day. The following day, I received a vat and duty request for the same package from Imile. I went onto the app I ordered from and saw that buffalo is not my delivery partner, Imile is - so I paid that tax too. I contacted buffalo and got no real assistance - eventually a week later my package arrives, delivered by Imile. I then send buffalo (a 5th) email with all the proof etc. They confirm my order is cancelled and they did not render a service ie they did not deliver anything, and send me a refund from. Great, I fill in the refund form and send it back. No response. I then call and am told I need to provide a proof of payment - which I request from the bank and send - no response. I then call back and am told my proof of payment is not sufficient because it’s a proof of transaction and not a proof of payment. I explain to them that I did not make an eft, I paid via their online card payment (mustang pay) and therefore only have a proof of transaction ( and a confirmation email from buffalo that they received my payment). I was told the proof of payment needs to have their account number, the reference, transaction date and my account number. I explain again that you can’t acquire a proof of payment like this for a card transaction - only a proof of transaction (which has the transaction reference, my account number and the date and amount). I called the bank again to double check, called buffalo back and when I said I can’t get a proof of payment because it was not an eft - I got a snarky comment on the phone “well we’re not refunding you without one so I guess you won’t be getting your refund then”. I have called and emailed them about 15 times respectively. Quite literally the worst customer service I have ever received.