my tamron 17-50mm lens my most used one is bust dropped it on xmas on a carpet floor and left it in the boot where it was soaked right through again now it only zooms up to a little past 35mm and cant get any further but it zooms back in ok to 17, was considering sending it to https://www.criscam.com this is good idea? anyone else had this etc

Personally, I've never dropped a lens.
Your site there is based in the US, so why not pick up a copy of Amateur Photographer and see if there's a UK company that'll service it for you?

You could try these:

http://www.fixationuk.com/Fixation/Repairs.html

or these:

http://www.hlehmann.co.uk/index.html

or even go to Sigma directly.