Reversal of money

My way debited my account on the 17th of July in error after I had cancelled my policy with them. I have since been making several calls asking for the reversal of the premium money that they took. Every time I get told that they money will reflect in my account within 7 days to date I haven’t received anything from them and I always have to call them. Honestly this is very frustrating and I feel as if im being taken for a fool because ive been promised lies!