Once again its an empty promise

I have been battling for 10 months now, from my first complaint I now have an FNB account but for some reason there is still issue with my credit card - I have now been charge interest and my credit limited has been lowered and I have not even been issued with a Credit Card. The branch Manager at Bracken City had promised to sort this out and reinstate my credit limited on my credit card (which i don't have) and to have the interest fee's revered BUT this has not happened. This has truly not been easy and I'm not sure what needs to be done as I have phoned and gone into the bank with no luck - I think the best thing to do is cancel my account..... don't know what to do anymore?????