Billed incorrectly

I had a Virgin Active membership which I cancelled a couple of months ago. In October 2015 I received a call from one of their agents offering me a free 3 month membership. I was only going to start paying in February. I did not confirm with her as she was going to come back to me. On the 1st of December an amount came of my account. I called to query this, as I had not confirmed anything with this lady. They promised to come back to me but never did. On the 31st of December another amount came off. Today I called to query this again and twice the calls were cut, after the I told the second agent not to put me on hold as I got cut the first time. I asked her to call back if we got cut and she didn't. I need someone to call me back as I want my refund and I don't want anything to do with them again.