After unlocking apple id and sign in to iTunes I cannot unlock my iPhone
This is what it looks like when your iOS device is activation locked.

Bypassing it is practically impossible unless you are the original purchaser.


How can I bypass Activation Lock?


See that thread for how to get a hold of Apple's support, but basically you either need to re-enter the locking user account and password or you need the person that controls that account to log in themselves to http://icloud.apple.com and remove the lock against this hardware.


Regain control of the account that was used before to lock the iPhone
Unlock that device with that previous account
Activate the iPhone with your account to lock it to yours