Bad Accounts department/ poor services

We canceled our contract with them at the beginning of the year. They still try to deduct from our account (twice successfully) after the cancelation and we do not owe them anything. We struggle to get our money back. Each time we phone they have excuses and advise that we send a mail... how many emails do you want until we receive feedback? This is unacceptable. give back our money and remove all details that you have on file!!!