Release the port or adjust accordingly

Started off well. Great interactive UI. The backbone company claimed to have to have installed/activated the fibre line in my house and I got invoiced. I sent images of the ONT to prove that the line was not active as the backbone supplier had alleged. The line was only installed the next day. I gave them the contact details of the installation agent. Cool Ideas insists on elevating their opinion into a fact. They refuse to adjust the invoice accordingly or simply remove themselves from the port so that I can use another service provider.