Unathorised debit orders

Unathorised debit orders from afrihost go off. They bounce due to the amount they want and the fact that I did not know about these debit orders (I am not now nor have I ever been a customer). I then incur bank charges for these debit orders. Afrihost kindly not credits the invoice, but then expects me to pay them fees for unsuccessful debit orders??? MAYBE DO NOT TRY AND TAKE MY MONEY WITHOUT CONSENT????

I cannot plan for debit orders that I do not know about from companies I have no relationship with?? How does that make any sense? This is happening every month and when they deduct on pay day and successfully get a grand from my account, they then take weeks to sort it out and once sorted it takes two weeks for the money to reflect in my account and when queried the response is this is our policy. Why does it take two weeks to return money?