University is not issuing me my convocation certificate I completed my bachelors in Engineering in Aug '16. It's been more than 2 years I haven't received my convocation certificate. Every time I go to university to ask about my convocation certificate the department head says they sent it to college. College says they didn't receive it.

Not sure what I can do more about it. Everyone is rude and they don't have any answers when i question about proof or written statement about my convocation certificate.

I am out of options and thinking of filing formal police complaint. If anyone has any other suggestions regarding this please let me know. And I am sorry for my earlier offensive post.
Assuming that it is a lack of communication that is causing your problem, you need a way to create the needed conversation to get the problem resolved. 

I'd suggest sending an email to both the department head and the college office explaining the difficulty and asking for a resolution. This should be one mail, addressed to both offices so that you put them in direct communication with each other. 

You may learn something from whatever response you get from either or both parties. If the problem goes beyond communication, you need to know that in order to figure out what else might be done. 

But you need, also, to phrase things respectfully, even if you don't feel it. Calling names such as you used in an earlier question here will only get you ignored.