Brik.
when i read your post my memories came flooding back.about 2 months ago my brand new beautiful house was tiled by a friend of mine. he did the bathrooms lovely , ensuite perfect etc. all the main bathroom was tiled and looked class. i gave him polished porcelain tiles for the whole ground floor i.e. downstairs toilet, kitchen,hallway,utility. he never leveleed the floor and they are a mess. i would have to buy 45 sq yards to put them down again. you cant take up tiles without breaking at least a good few of them and the rest will be ruined with adhesive. your tiler was a cowboy as was mine. i had mine only paid half the money and he is coming back. but all he is going to be able to do is replace about 10 of them. we have taken to strategically placing rugs around the house to hide the worst ones and to be honest its working. no one notices them. like you i wanted my polished porcelain tiles to be the showpiece but i have spent thousands on them and now need to cover them. all i can say is that you have learnt a lesson the hard way, as have i. i have decided to leave them now, cover the worst ones, get him to take up the really bad ones . if i decide to stay in the house long term then in a few years i will get them taken up, floor levelled and tiled properly. hope this helps. its not as bad as you think. belive me