Life cover cancellation

I have already called the call centre wanting to cancel my life cover but on seperate calls have they told me that 'they will get their cancellation department to call me' and that was 2 weeks ago but yet I am still waiting for them to still call. I have already taken up another life cover with another company and I do not wish to continue with their offering. If I made a request to give them new business THEY WOULD HAVE CALLED ME ALREADY.