The pill

I've been using the pill called Cerrelle and the first month I used it I was fine and then when I started my second month on it I had what I thought was a period and then after a week I bleed again and now I haven't stopped bleeding for 3 weeks. When I speak to the doctor he just says that I should wait but I'm getting really fed up of being in my period 24/7. Does anyone else have this problem with this pill? What should I do when the doctor won't let me change pill??