A creditor can't call in the bailiffs until after they've first obtained a County Court Judgement against you AND you've then defaulted on that judgement. If you've got no CCJs at the moment, you have no need to fear a visit from bailiffs. (For many people a CCJ is a good thing, and not something to be feared. The court fixes a realistic sum for you to repay regularly and, as long as you keep up with the payments, you're protected from further hassle regarding the debt).
As others have said, contact CCCS:
http://www.cccs.co.uk/
Chris