I understand how annoying it can be when someone blocks you on whatsapp so that you will never send any message to him or her, or even to know when his online or offline.
I don't know what you did to the person that made him/her to block you and i suggest you don't keep playing against somebodies rules but that is by the way.
Am happy to let you know that you can really unlock yourself if someone blocks your own whatsapp but first you need to be sure that you are blocked.
How to know if your are blocked:
Usually when someone blocks you on whatsapp you will stop seeing that persons status and your message will never be delivered to that person.
How to unblock yourself when someone blocks you on Whatsapp:
Now let me show you how you can actually unblock your whatsapp profile when someone blocks you, all you need to do is to follow this simple steps blew:
1 As i said earlier firstly Check If Your Friend’s Profile Picture or Last Seen or Whatsapp Status Are Visible To You or Not, And If Not Then You Are Blocked then you need to open Your Whatsapp Messenger
2 Now you will need to goto your whatsapp Settings and Click On Account to delete your whatsapp account (Don't worry you will still get your account back)
3 After following the above steps its time to enter Your Mobile Number And Delete Your Account after that goto your mobile phone application menu and Uninstall the installed whatsapp.
4 After Uninstalling the whatsapp from your phone then restart Your Mobile phone and all the old data will be erased.
5. Download and install Whatsapp again and fill your Mobile phone Number and other required details, after that connect your whatsapp again and you are unblocked from anybody that blocked your Whatsapp Account.