What to do when approached to redo dodgy tiling?

[IPeterson]

An older couple had me over to take a look at their bathroom and get them a quote to redo the tiling. They had someone in early jan that has done an awful job, left it half finished and they cant get hold of him. It all needs removing and starting afresh, its a lot of work but they already paid this guy so much, I feel bad having to charge them again, but its going to be a lot of work and materials. He even damaged their new bath theyd had fitted. I really feel for them but am not in a position to do the work for free. Is there anything I can suggest to them? To try and recoup some of their money?

[wine~o]

If the original cowboy has vanished not much more you can do other than quote honestly for remedials and put out his name on social media in the hope that he won't get any more work.