Need to know how to unblock a blocked bank account

There isn't such a thing as a "block" on a bank account, not as a legal term anyway. It may be that the money was set aside and placed in your parent's control until you turned 18. In that case, if they're withholding the money, you may have a suit against either them or the bank, depending on the specifics.

Please elaborate on the reasons for the block, so we may assist you with a 'go-forward' model.

In order "unblock" the account, you need to find out the terms under which it was "blocked." This means you need to obtain all of the documents that relate to the creation, ownership, and administration of the account. Once these matters are understood, you can then determine how to get access to any funds that are in the account. An attorney can assist you with this. Many attorneys offer free initial consultations.