Police Abuse

I'm facing multiple cases of police/LASMA abuse on the road and believe i'm not the only one. Sometimes you can be in traffic for hours and after you pass congested place you see officers just chilling around and waiting for next prey. If you try to direct them to solve the traffic issue arround they tring to berate and hit you with stick as a main cause of traffic. But if you go empty street on weekend they stop you to check you particulars and asking "smth for weekend".  And if you did smth/ wrong you are in trouble because they have plenty time you do not have. So they use their working time to abuse you and waste you time instead to do theit job. Usually they just stop you, collect driver's license and live you for some time to think what is your time is more valluable then some money you can give them to go.
Is here any lawer who can explain Nigerian traffic law in the part of vehicle arrest. I have a situation when my driver go wrong direction on one-way empty street in VI on Saturday morning and was cached by police officers from Bar-beach police station, who surround the car in number of four trying to enter parked car. 
I was ready to let driver go with them to solve this issue in line of law but they reguest to give them car to transport it to police station (if driver make a mistake why car or passangers should be limited in their constitutional rights and suffer). In the end after one hour discussion with them while they do not allow passengers to live the car, they brought a tow-truck and transport my two-weeks new car to Bar-beach police station pulling it up by front bumper painted in body color and crushing it. Finally they request 40k to be payd for their let say "traffic regulation law-enforcement services" but got 20 and was happy but didn't make any report or issue any fine receipt for money been paid. Sure this money make their weekend better but God see everithing and he act.
Is here any lawyer who can can explain if police can behave like this abusing people, arresting car and ask for non resonable money. Is here in Nigeria any government body to control and penalize such policemans? Is there any official law with penalties according to traffic offence?
Thanks

shio