This is standard practice, and unfortunately having accepted the T&Cs, you do not have a legal entitlement to a refund. The NCA were talking recently about trying to get such clauses removed from contracts, particularly gym memberships which they receive a lot of complaints about.
That however doesn't stop you contacting them and appealing to them to allow you cancel without penalty. If they are willing to do this, they'll likely take 1 or 2 months as minimum notice, whatever period is stated in the contract.