Buffalo changed to the worst logistics company in South Africa

With reference to my previous complaint regarding Tracking no BUFZA7DB01066QSYQ My previous complaint explained how they accused me that I have received the parcel. After many emails to them they eventually realised that I'm not going to accept their story and agreed to refund me. It is now nearly 2 months since they promised me the refund but every time delaying it, saying that my proof of payments are not correct. I did forward them the proof of payments exactly as the bank has send it to me MANY TIMES. They are trying to irritate me, hoping I will eventually give up. BUT I WILL NOT - a logistics company like Buffalo should be thrown out of South Africa. About 3 years ago when they started in South Africa as a Chinese owned company they were fantastic, but something has happened to the Buffalo I knew and they have changed to an unreliable and unstrustworthy logistics company