Unauthorised debits after cancellation.poor service

Ive sent several emails several calls were made i cancelled my policy to no avail then even took a higher insurance in its place a new policy then u still debited my mother who is the payee of this old policy she has now had to put in a bank reversal which cost her extra money i confirmed on my last phone call that i cancelled policy and u said its in order ull debit my new policy off my new account the 3rd. Im extremely unsatisfied with this poor service. Stop orders and reversed debits cost money now im losing money on my behalf thanks to poor service i request a resolution asap and refund of my extra costs or alternative compensation for my losses on old policy.