Virgin Active billing me for cancelled Swimming contract

I signed up my child for swimming lessons, I was not happy with Virgin Active manager's stance on us forfeiting paid for lessons especially those cancelled due to the instructor being ill and subsequently leaving. I gave well over a month's notice of termination, yet I am still being billed. Their manager Wendy has promised to find out from the 'high ups' regarding my refund and continued billing, its been over a month. No feedback and no refund.