Glad to hear your problem got taken care of.
I have heard of many problems with this install but I haven't heard of problems with defective coil spring cartidges. This install can be difficult as there is the potential to break anyone of the connectors as they can be difficult to remove. I had broken one of them and I had to buy a new one from Tischer.
BTW many dealers will say that it has to be programmed etc and try to charge for it. No programming is necessary unless you remove the steering wheel angle sensor which will result in multiple errors. That is the most important step and as outlined in the step by step in the DIY by Doba, the sensor is not to be removed from the steering assembly.