Nigerian Police allegedly Harrases Student Because He didn't Give them Money for "weekend"

I am a student of university of lagos and I am presently writing my second semester examination. I finished my examination for the day and was heading for my classmate's house in onike sabo at about ‪1:40pm‬ when I was pulled over by two police men around Adeshina street in onike.
I stopped as I was requested to. They came down from their motorcycle and asked me where I was going and I explained myself to them, next thing I was asked for money for the weekend and I told them I didn't have any money.

They then told me that they wanted to search my car, hoping that will scare me all because I didn't oblige to give them money. I wasn't asked for my license or car papers which I expected them to.
So I asked them for a means of identification as I figured the motorcycle did not have a plate number  and I wanted to be sure if they were really police men. They said they wanted to enter the car with me. Not being able to identify themselves I refused.
They told me since I wasn't willing to cooperate I would be delayed. I still wasn't told my offense, not giving money as they requested for or not opening the vehicle for unidentifiable policemen to come in.
After a while one of them told me to move, I started the car and he used his gun to break my side mirror. I pulled over to challenge him, and he told me the money I refused to give them I should use it to fix my car mirror.
I brought out my phone took his picture and told him I would take it up. He told me he would use his gun and seize my phone. He dragged my phone and in the process my phone screen cracked.
I challenged him and was calling the attention of people around. They noticed people  around started coming, and they quickly started their motorcycle and zoomed off, leaving me with a broken side mirror and a cracked phone screen.
Refusing to identify their division or produce their ID cards, but fighting back to make sure they get the pix I took, deleted, or take away my phone, indicates that they were doing an illegal work."