Disrespectful and bad Attitude Staff

I've tried calling and emailing Virgin Active to cancel two memberships, that of my daughter and my personal one. Todate I still await the courtesy of a response to my email! I resorted to Twitter messaging to do the cancellations. VA will cancel my membership but not that of my daughter. She was a minor when the membership was activated and I pay the monthly fee. I'm told by a disrespectful and nameless Twitter representative that I cannot give instructions to cancel her membership. I have given the instruction and expect the cancellation of the two memberships. Failing this I will return any debit deducted against my account! I will not be bul**** and treated disrespectfully by Virgin Active staff!!