Most subscription services have a cooling down period, which can be a couple of weeks, or even up to a month. You could ask if they could accept you leaving with X amount of weeks notice. I don’t think that by looking at the name will help you too much. Try to get them on the phone to explain the situation as a first step. If they refuse to budge, then you could consider getting your bank to cancel the direct debit. It’s unlikely you’d face legal action brought against you by a local karate club when your son is no longer even attending. If you have already paid for an entire year in advance, then that may be more difficult. Alternatively somebody else on here may know a bit more and will be able to offer you more informed advice.