Thanks everyone for your replies. We had someone in yesterday to have a look, ironically it was the guy we originally wanted to get but he was really booked up, we know that he comes highly recommended. He was horrified at the state of the tiling and said it was a complete mess. We'll have to cut our losses and buy some new tiles and start again including replasterboarding as the old stuff was soggy from the adhesive. I know that it hadn't been 48 hours (I think the tub the tiler left said it took 48 hours to set) but the mosaics were just peeling off the wall last night. My husband took some pictures before we took them down but would need to upload.
I'm relieved that the tiler only spent a day on our bathroom, had it been longer I don't know what we would have been left with.
By the way, the mosaics were 8-9mm and the trim was 10mm, I was told that this would be OK. I have taken the trim down and washed the adhesive off so we should be able to reuse some of it.
This forum is great, I will definitely keep it in my favourites as everyone is so willing to help.
Thanks again.