ANet does not actually merge accounts. What they 'sometimes' do is disable the key on the old account and issue you a new key so that you can get the activation right the second time around. Anything on the old account is lost.
Most likely the OP was sharing an account and now wants to get his/her own account.
The answer is "No." You cannot transfer a character between accounts.
@Dargon - I believe it is the other way around. ANet disables the new account and issues a new key to add to the old account. This requires proof that you purchased/own both accounts as new and did not purchase a registered key from someone else.
the only thing you can do is move your noncustomized stuff to the new character on the new account......if you want the characters you would have to recreate them, and if you wanted the same names, you would need to wait an hour after deletion for the name to become available again (and hope that no one else took it in that few ....interval----).