Car insurance?

Last year i paid my car insurance in one hit, online. this year, renewal price was higher because i got £50 cash back last year. i saved £120 by searching around and went ahead with the new deal. unbeknown to me the first company renewed my insurance without my knowledge because they had my credit card details from the year before. i ended up being insured with 2 companies for 3 days and i went £109 over my limit on my credit card. not only is it illegal to be insured by 2 companies at the same time, they did it without my knowledge! are they allowed to do this? i have, i hope, resolved it but if any charges are incurred either for cancelling my previous insurance or going over my credit limit are these retrievable?
Answer
They first insurance company should have sent you a renewal letter stating if you did not cancel they would auto renew, however if you have cancelled afterwards (within 14 day approx) there should be no charge! plus as it is a minor error the police would not charge you for being doubly insured!