[earleygallery]

Well, they should have contacted you when they realised they couldn't replace the front element to ask you if they should proceed with the CLA anyway.

I'd definately complain about that and ask for a lower price on the basis that they didn't carry out the work requested/promised. Not sure how this stands legally but would sound like a breach of contract to me - I guess you just want the lens back so try for an amicable solution first.