Hi,
You have every right to complain. You should, though, read any small print associated with the holiday/charter company as they may have a disclaimer regarding personal equipment. They may try and lay blame with each others insurance.
At the least you should be entitled to the cost of servicing your reg. Do you know anybody (chemist/ry student) who could identify what this powder is, is there any left? (I'm no Chemist but white powder, and possibly Aluminium corrotion, strick me as no coincidence? I know Alu, is not supposed to corrod byt??? If your able to point out what they may be doing wrong (in contaminating the air supply) they may be more willing to help or provide compensation.
At the very outside chance they tell you where to get off, you could remind them your part of a large group of british/international divers (give them the website) and remind them how bad customer relations can severily harm their future business.
Dave C
Good luck.
