MONTHLY PLAN - Credits for Lessons Cancelled

How do I reclaim a credit when a lesson is cancelled by Swimtime if I'm on the monthly plan?

The idea behind the Monthly Plan is that your account balance is always £0.00. If we cancel a lesson and apply a credit to your account, your next monthly payment will use up that credit, so the amount you pay that month will be less.

For Example: If you pay £40.00 per month and have a Swimtime balance of £10.00 credit on the day your monthly payment is taken, only £30.00 will be taken from your card.