Renault Clio immobilizer

Hello, I assume that the topic has already been dealt with here, if yes I apologize for it. I urgently need help. With my clio a plantine on the key has broken off. A friend of mine could solder it again, but now the immobilizer does not go out and the car does not start. I have to say that I bought the car used and only one key. However, the immobilizer has caused problems from the beginning and I am already at the unpossible After the soldering of the plantine, the automatic door lock now works again, which did not work before. I therefore assume that the key has been repaired well. No one wants to help me with Renault. I have never been treated so condescendingly as with all Renault dealers in the last few days. I can only explain this to myself that my car is already older. , built in 2002. According to Renault, it is not possible to reread the key or enter a code. I am supposed to have a new lock or something installed, which costs me 600 euros. My car is not worth that much, although it does not cause any problems. Do I have to scrap my car now? Maybe someone can help me… I’m really desperate. Thank you very much.