Poor products (welding machine) and worst after sale service

More than a year ago I got a Smarter ERA-150 welding machine from Steel & Pipes for Africa in Pretoria. It worked for two minutes and then stopped working. I returned it to Steel & Pipes now three times - the last time we tested it at the shop and it was working fine same at my house but for only about a minute where after it ceased to work again. (that is what happened everytime I took it back). I begin to look like the idiot everytime I enter the shop. I then put a message on their webbsite and needless to say - no reply, then I phoned the company to discuss the problem. The call ended at the swithbord - no response at all. Then I sent an e-mail to the second in charge of the company (Jackie) at *** needless to say no response. This is the worst service ever.