This place will only cost you money

We Bought a New Ecu from them for R9000 and sent it to them with the Old Ecu as they requested it for programming the new Ecu. Eventually when we got it back the car now has an Engine Error code for the Key. We took the car for diagnostics which confirmed that the Key chip for the Ecu was bridged out, that is why is showing the error. We phoned Ecu Express a few times where they kept saying the main Technician will phone us back but he never did. The next time we called, the guy on the line said that our old Ecu must have beem faulty, that is all reason why they would do that and that we should take the car to be Reprogrammed at our own expense. We phoned again a few days later and they said the Technician is busy he will phone back. Again never phoned back. We want to sell the car now how do we sell it with a Engine light on. They refuse to help and we struggle more and more to get a hold of them. So now we must just pay someone else to fix their mistake?