I was advised that I would be paid a dreaded disea

I was diagnosed with breast cancer, I put in a claim against my dreaded disease on my life policy, they made me fill out forms over and over, they never contacted me and I was treated like a number with a claim, nothing more, they said there was a cession on my policy, which was incorrect, when I asked for a copy of the cession, suddenly they said there wasn't one, so the claim was now going to be settled, this is almost 2 months later. On Friday I received an e-mail stating I had been approved for level C that being 50% of my benefit. They then proceeded to pay out an amount that was not 50%, I called them and was advised that they had paid on level D, when I asked why it wasn't paid in accordance with their approval letter, first I was told that I had not been sent such a mail, and so I forwarded it to the person while on the phone, then I was told that that was a typing error. After that I received an e-mail showing the payment breakdown. This morning for the first time since my claim was submitted I was called at 8 o'clock - first thing! to be advised that it was an error. I do not accept this and have advised them that they have to pay out according to the level I was advise