If you tell us the reason, we could help you more.
But in the worst case, reasons such as "you dislike TUS", sadly we can't delete. You can simply leave your account abandoned.
Accounts hold too many information and have a very close relationship with other members/parts. Deleting account won't make sense, since there will be places that requires you account, such as games. (e.g. your opponent is on the other side of the game)
TUS policy is to store everything from the start.