Hello,
In case the police is not conducting the investigation in a fair and proper manner, then you have the following remedy available with you:-
1. Give a written representation to the SP of the area, enumerating the entire facts and circumstances and ask for change of the investigating officer. The SP may direct change of IO or may direct a senior police officer to conduct investigation in a fair and proper manner.
2. In case the above doesn't work, then file an application before the magistrate u/s 156 (3) praying for conducting a fair and proper investigation in the matter. (Sakiri Vasu vs State Of U.P. And Others). The magistrate can call for status report and direct the police to conduct fair investigation.
3. Even after availing the above two options, if nothing happens, then file a petition u/s 482 CrPC before the High Court seeking a direction of proper/fair/change in investigation.
The above remedies can be availed by both accused and complainant party.
Further once an FIR is already registered, the scope of registering another FIR at another police station is not available. Even if you have to level charges against the police officers, the best way is as enumerated above.
Regards,
Nishant