Poor service and rude consultants

The level of service I received from this company is appalling. Consultants are very rude and they drop calls when I ask question. After settling my account in full, they still went ahead and debited money from my account and they do not want to refund that amount. Additionally the debit order that went through, I had cancelled it two months prior and it wasn't deducted, only for the debit to go through after the account was settled. I feel like this is *****, the unfortunate part is that this company is taking advantage of people who are already in debt.