First of all, is the content of applying to join the company (that is, the door) the same as or consistent with your business content? Whether it is in the same industry or not, if it is not in the same industry or the same or similar, it does not constitute infringement and does not need to bear any tort liability.
Secondly, if you can prove that the method you used in the operation was advertising cloth and the door head was left by the former boss, you can prove that you did not use the door head of the other party subjectively, there is no infringement fact, and you do not need to bear tort liability.