Online Carparts don't refund.

In December 2020 I asked for a quotation and availability for the correct alternator for my 2007 Chevrolet Lumina SS 6.0L L98 engine. In February 2021 I managed to get a quote for R4500.00 for the correct alternator. ( Their list price is R4250.00 ) I made a immediate payment of R4500.00 Then after quite some time they send me the wrong alternator. I told them that the new alternator does not have a clutch pulley , and that's actually why I buying a new alternator because mine's clutch pulley broke. Then they wanted me to send the wrong new one back with my old unit to make one of the two, I advised him that It's not possible because the clutch pulley is broken in mine and that theirs have a solid pulley fitted. I advised him that if he can't supply the correct unit for my model vehicle, then please just refund me on the 23 March 2021. Thats were all the refund promises and lies started between Theo and a lady called Nadia or Nadine. I even drove to their Randburg office and they advise me that Theo is no longer working there, I asked to speak to Nadia / Nadine, she first didn't want to speak to me, after a while she came to the reception and with a very arrogant attitude told me she will not refund me in full. I paid R4500.00 plus R180.00 courier cost and traveling 40km to the courier and 40km back sendind the wrong unit back. I have made numerous calls to them , they all just ignore all my attempts to communicate. I have send e-mails which they also just ignore. No one is willing to refund me in full nor communicate with me. I have all the whatsapp's between Theo and myself on record. It's now 7 months, no attempt from any of Online Car's management to resolve this matter.