We initially received a request to accept a job via email, we spoke to the contractor and gave our prices per sqft and he accepted, we received estimated measurements and proceeded with estimate, but told him this was based of his measurements. We went out and took measurements and there was a 1000+ difference. The only contact we had was with the customer since the contractor wouldn’t answer our messages or calls and customer wanted a change on the project and we complied with her demands. The job was complete and the customer loved her kitchen. Contractor did not answer when we needed to get paid, I had to hunt him down and finally we met at his storage unit and he paid with a check ($4004.17) and 2 days later sent me an email saying we stole from him and that we were gonna see what he was gonna do next. He stopped the check my account is negative -$4000 and he is going back and forth with us that he will pay us what he wants not what the final invoice said. He’s threatening us if we don’t give our SSN so he can file a 10-99 that we will get audited by IRS. Please help