Contractor not sending final bill

[Matt Wharton]

Three weeks go, we severed ties with a contractor for several reasons, mainly poor communication and reliability issues. We've been asking for the final bill from them ever since and got an email back two weeks ago saying it was going to be sent out that day. Last week, we sent another follow up email with no response. Friday came around, so we emailed multiple people within the company that basically said "please send us a final detailed invoice within 2 business days, or we will send a check based on work completed and prices previously quoted." They sent us a detailed quote for the work that would be completed before they started, so we know the agreed-upon costs except for the cost of additional materials that they did purchase. We just want to pay them so we have a better handle on the exact budget we are working with for the rest of the project. I've never come across a company that did not want to get paid for work completed! What would you do/what have you done in this situation? How should this be handled moving forward? Thanks BP!