Buying a product and paying by EFT whilst far is not not advisable.

Bought an engine from them in December 2021. I paid through EFT because I was desperately looking for an engine. I paid twice for the courier because the guy lied saying he paid for the courier of which the Bigfoot company denied. They have not delivered the engine to me yet. I paid them R 56000. Now the guy insist that I must come and collect the engine and bring the old one. He claims I want to rob him and I am a liar even though he has my money and he has not delivered the engine.