HOW TO UNBLOCK WITHOUT LOADING THE BLOCKED USERS LIST:
sometimes you find its difficult to load your BLOCKED USERS list. in such a situation you can use this trick.
to do the trick, follow the steps below:
1. Delete the person from your contact list. ( the person whom you want unblock)
2. And again add him/her to your contact list.
3. Now he/she will be unblocked.
NOTE: if the person is not in your contact list, you can add him/her. and the person would be unblocked