Incompetency

The staff is highly ***********, I am on maternity leave and I contact the store a number of times to cancel the debit order and make manual payments. Every time I call they would take my details and promise to get accounts to call me back and no one ever did so I eventually went to the store on the 3rd December 2018 to cancel the debit order the lady that assisted me assured me that no debit would run, now the debit order went off yesterday and returned upaid and my account is on a minus who must pay for these charges? My contact number ********** 673.