That sounds like a very frustrating situation, sorry to hear it.
I've only needed to use them once, to rebuild a Skoda Octavia ABS module. VAG cars had them going all the time several years ago and refused to recall in typical VAG group fashion. ECU testing were about 1/3rd of the price of Skoda. Speedy, reliable and efficient they were too, hence I was very happy to recommend them.
I have a friend who is a mechanic, and he uses ECU testing all the time. They are more reliable than BBA reman from his experience.
I think I would be asking to scale this up to management level at ecu testing. They really should get this sorted asap or give you a full refund imho.