Distance selling regulations (DSR) refund? HELP?

[sebastiano]

I paid for an online course (in the UK) but cancelled it within the 7 days, and it's been 32 days and I haven't recieved my refund. by law, they're meant to refund within 30 days.
I contacted them and they said they don't know how long they will take to refund my money, which is so stupid! it was meant to be done within 30 days!
who do I contact to get my refund is they don't refund the money?
I paid by debit card.