Hiya!
I'm afraid HanSoloDK is correct - we don't have the permissions to make any changes to a Garena user account.
If you'd like to make changes to a Path of Exile account that was previously connected to the Garena service we may be able to help with that. You can make those requests to our Support team at [email protected] - please provide us with the account name and 1-2 character names on the account when you email and we can locate the account. :)