There are a few people here who can help you through pm, but here's all I know
You will need to know every detail of the account possible (multiple passwords, email changes, pet transfers, multiple pins, specific items in inventory/equipped/sdb/bank balance/shop til balance), and for a high profile account they have probably changed their info repeatedly. You also will need to contact them from multiple sources, report a ticket on a noob account - created from the same e-mail as the account you're trying to get unfrozen. Also it's probably worth emailing staff directly, some people have much higher success that way. Some people have also said that reporting it to BBB has got more response from tnt.
Lots of variables that is best handled through pm with someone knowledgeable will affect the outcome, like what the account was frozen for, what information you have, etc