FNB home loan’s very bad service

I have a home loan with FNB and I want to move to another service provider as they have better interest rates. When the lawyers request for a settlement amount the amount is way more than what my loan amount was for,how when I have been paying for months but the amount is going up instead of down. You can’t get hold of anyone to give you proper feedback,you get sent from one person to another and no one will give you a straight answer. Mind you this “transfer” has been going on for over 6 months and every 3 months review the amount keeps going up even more than the previous settlement amount provided which I am still questioning with no feedback. I have not stopped paying since the cancellation request but this is frustrating because FNB can’t provide me with a better interest rate even though I have been their customer for over 20 years and when I want to leave they are giving me the run around. I want to leave please assist in this transaction!