Vitality being billed even now

I took Vitality with Discovery Consultant, I was signed up over the phone and on the 25/08/2015 I sent a cancellation and was informed that my cancellation is being processed. I was then called by an agent trying to retain me and I indicated that I cancelled the Vitality. The consultant doesn't advise me that if I cancel with them it will not be cancelled but tells me to stop it with my company. When I tried to stop this I was asked a proof from Discovery regarding the cancellation but I did not have. I sent an email that says my cancellation is being processed but the HR department said Discovery is still billing them. I want my money to be refunded as from the day I cancelled with Discovery. I called in November but I was not assisted and now I am billed again. I don't think is fair to sign me up via call center and when I want to cancel with the call center then I do not get any assistance.