Bad tarring

I had a Tar job done in Tableview by Mark, who goes under your name. He insisted I pay him upfront as he said he was giving me a good price, so I did. When the job was completed and one could not see how the job was because it was dark and also looked fine, he demanded the last amount, which I paid in good faith. The following day, I noticed lines and bumps in the tar work and later on after further investigation, it was evident this was a real bad job. Apparently the tar is only 10mm thick in loads of places, and it already coming apart. When I contacted him about this, he said he would meet me on site, but he never showed up. Even after multiple phone calls and e-mails, it became evident he was not interested in rectifying the bad job. I eventually called my lawyer who spoke to him. He told her he would phone me. That was two weeks ago, and still nothing. I phoned him a couple of days ago and left a message, but that has been ignored too. Very disappointed.