FNB taking advantage

I approached FNB for a further lending amount on my existing bond loan. They offered me this but on a higher interest rate than my existing rate. This meant my existing bond plus further lending will then be calculated on this higher rate. Not being happy with this and not understanding why the big change as it has only been 10 months since I have taken out this bond loan and my credit rating has not changed at all (no big purchases nor debt made), I emailed FNB to please reconsider and take into consideration my 16 years of banking loyalty to them. Their response was they cannot due to their \pricing strategy". Is FNB motto not \"" how can we help you\"""