When I was an adult of sixteen, still having never performed Hajj on my own behalf, I knew that it was impermissible to perform Hajj on behalf of someone else before performing it for myself. However, I was forced to perform Hajj on behalf of someone else even though I tried hard to explain that it is impermissible to do so. What should I do now?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Scholars have held different views as to whether or not it is permissible for one to performs Hajj on behalf of someone else before he performs it for himself. Those who adopt the opinion that it is impermissible say that if one does this, then the Hajj he performs would be counted as his obligatory Hajj.
Hence, you have fulfilled the obligation of Hajj according to this opinion (which is the opinion of Ash-Shaafi‘i and Ahmad ); and this is the preponderant opinion.
However, Maalik and Abu Haneefah held the opposite view to that.
So if you want to avoid being caught up in the difference of opinions among scholars, perform Hajj for yourself once again.
You should know that the obligation of Hajj was not fulfilled for the one who authorized you to perform it on his behalf or on behalf of his deceased relative. You should first inform them of this fact and if they gave you any money in return for performing Hajj then you should return that money to them.
Allah Knows best.