i have had so much trouble with 3 and i have 2 contracts with them, im cancelling mine when they run out shortly. anyway try phoning this number as this is what i was given from otelo an official complaints dept for this kind of thing 08707330272( its 3's officail complaints office, and they were very helpful) although you might find that you have to go through otelo first to get a complaints ref number before they do anything this is the website
http://www.otelo.org.uk/ good luck let me know how you got on