We started this job on 9-14-2022. The job was for an HVAC replacement and was set to replace the condenser unit and the evaporator coil. The day before I found out that the condenser unit that I listed in the contract was unavailable until the following week. So I found another similar unit. We arrived at 9am on the 14th and informed the customer about the equipment issue and gave him the option of having us install the equipment we had or we could come back when we had the unit listed in the contract. The customer verbally agreed to have us install the replacement unit. Later in the day the customer started having issues with the way we were working. He was concerned that we had brought an evaporator coil that was slightly longer than the one that was originally installed in his house. He became so upset with this that he tried to cancel the job but I talked to him and assured him that fabrication for an HVAC replacement is normal on every job and that the unit would work just fine. He agreed and let us continue. Towards the end of the day my employee on the job was trying to install a new disconnect box and was looking for the breaker so that it could be done safely. In the process of doing that he mistakenly removed one of those tamper locks on the electrical meter. The customer was very upset about this even though I assured him that I would pay for any fines from PG&E. Towards the end of the day the customer became more and more troublesome. When one of the workers left the attic to help the other one outside the customer would go up into the attic and take pictures criticizing questioning our unfinished work. After the workers left the customer went back into the attic and sent me photos of the work claiming that the workmanship was bad. The next day I went back to complete the job. My workers were unable to charge the AC system the day prior. At that point the customer would not let us back in the house. He was claiming that our work was bad and unsafe, that we had "unlicensed" workers on the job, and that we installed the incorrect equipment without his approval. Since then I have given him 3 options. 1) We come back with the equipment that was in the contract. Then the system would be HERS rated and inspected. 2) We can finish the job with the existing equipment and a signed change order. Then the system would be HERS rated and inspected. 3) We can cancel the contract, return his money and take the equipment back with a signed document stating that he is satisfied and will take no further action. He has refused all of the options and says that he wants his money, gets to keep the equipment and will not sign anything. The customer is under the assumption that since we installed the incorrect equipment, that entitles him to all his money back. I believe this to be incorrect and as such we have made several attempts to be in compliance with the signed contract. Also, I found out when I pulled the permit that the man who signed the contract is not the property owner who is listed with the city. It's my understanding that this is illegal. Please advise.