Wrongfully takes money from bank account sporadically. Not in a hurry to refund.

I prepaid for a year, then was told they can't load me onto the system without a bank account. I was worried about them taking money through debit orders but still stupidly went ahead. Now I have to check every month whether they are debiting my account, started 6 months after joining, 6 months ago. I've been constantly complaining and requesting refunds, but until now no one has managed to return my money.