Treating customers fairly- Failed

I recently had my home loan amount increased and had the pleasure of dealing with all the paperwork involved including have too sit with the standard bank appointed legal team who explained line by line what each cost meant. Imagine my surprised; when the first installation came off and the insurance amount which was agreed upfront changed by an additional R100. I logged a call for an answer - no luck. Second month the insurance increased a further R100. I tried again calling and was transferred 7 times between home loans and insurance that I needed to escalate the matter too the Prestige line. The consultant then; had no luck with there own internal department who took a further two weeks; and ignored follow ups. Is this the way a business conduct itself? Then; eventually feedback was received. A simply answer oops; we calculated your premium incorrectly. How convenient that a bank just increase premiums as it sees fit and then say oops mistake but please pay more; when you signed a legal document that actually said this is your premium. Thanks for treating customers fairly; I really appreciate it! And thanks for picking up the phone and informing me ( I actually only got the answer after having too escalating and screaming on the phone) seems the bank does not really care about treating customers fairly;

Rather take your business to another bank;