Exit after 3 years

You are not clear.

You can exit whenever you want if your sponsor issues you a final exit visa.

Iqama and vacation have nothing to do with each other.   Iqama has an expiry date.  Iqama has to be valid for the final exit visa to be issued.  If Iqama has expired, it has to be renewed for final exit to be issued.

no my issue is my 3 years will end on june,  but it is supposed to be feb.  I think they dont want me to go exit.

If you want to go before the Iqama expires, your only option is to approach the labor court and show that you don't want to renew the contract.  It's not going to be easy or quick.   Best approach is to agree something with your employer.

Is it right that my last day of work will be on the time that i came last year?  supposed to be,  i should have my vacation on february but i exteded it on april,  so i have come back on june.

Stop confusing it with vacation.

Your time period of employment is determined by your contract and Iqama.   That is it.   If your contract expires before your Iqama, you can give notice in advance.   If employer doesn't accept it, you can approach the labor court.