I know how you feel, TNT iced my original accounts, then after building up another account they iced me again (first time was for buying neopoints, which was total BS, second time was cause my account got hacked and TNT froze me permantly for my protection or some crap like that)
I sent several emails to TNT, ect, with no answer so I turned them in to the BBB (the Better Business Bureau) at www.bbb.org where they HAD to reply or get a bad mark.. at the time I was a premium user and my main complaint was that they iced me and then billed me for that months premium useage..
Dunno if the BBB will work for you but it might be worth a try when you've exhausted all other routes..