Contrary to popular opinion, very few contracts require a signature. If you buy something in a shop, you and the retailer have both entered into a legally binding contract. If you verbally agree to do my shopping for a fiver, we've both entered into a contract. If you park your vehicle on a car park, you've entered into a contract to pay the charges displayed. (Etc, etc). A contract can be entered to by word of mouth, by an action (or inaction), by a click of a mouse or in many other ways.
If you've agreed to keep up the payments for 12 months, you're legally obliged to do so. If you refuse to pay, the Entrepreneurs' Club can pursue you for the debt (including via court action) but the worse which could happen (apart from your credit rating being destroyed) would be that the Club could obtain a County Court Judgement against you. Such a Judgement would allow you to repay the debt at a rate which you could afford and (as long as you kept up the payments) no further action could be taken against you.
Chris