If you’ve been a victim of crime or believe someone is behaving illegally, then you must call the police on 101 for non-emergencies or 999 for emergencies. Your MP cannot do this for you.
However, if you have complained to the police about something that you believe they are not investigating properly, or you want to complain about the way you have been treated by the police, you can raise a complaint by visiting: http://content.met.police.uk/Site/complaints. If your complaint is not about the police in Sutton or London, then check their website or get in touch for the same details.
If you are not satisfied with the outcome of your complaint, then you can escalate it to the Independent Police Complaints Commissions (IPCC) here: https://www.ipcc.gov.uk/.