Old mutual ****

I have reviewed my bank statement and found out that old mutual have debited my account with out my permission since year 2016. When tell them about the issue they said I must submit all my bank statements dating from 2016 until 2018 so the fact is policies of other people I know nothing about were paid through my account. Now I my money back it is not their money, they tell me that I have no case can someone come to my rescue please.