Incompetence @ FNB

I recently settled my bond after following the required procedure i.e. obtaining a settlement amount and contacting my lawyer etc. A month later my account was again debited by FNB for the home loan which had ALREADY been settled. My wife then contacted them and tried to get an explanation as to why a further debit was made on my account. Unfortunately they fumbled for almost an hour but could not provide any excuse for incorrectly debiting my account. My wife then spoke to someone at the home loans department who promised that the money would be paid back into my account within a week. A WEEK later I received an email requesting that I complete a "refund form" before MY money , which they took from my account without my knowledge, would be refunded. I then received an email from ?Lara Duncan stating that they will not refund my money as my wife's signature was incorrect. I am not sure how this could be possible as I had previously used the same signature to apply for a rate review during 2021 and there was no objection. @Lara Duncan or whatever your name is, I have rep**** to your email. I would like to know that if my wife's signature was previously used as per the email proof sent, then which signature signature between the two are "*****ulent" ? If FNB have accepted the very same electronic signature during 2021 as the one which was signed on the refund form two days ago, what signature would you like me to see on the form??? It is due to FNB's incompetence that my account was incorrectly debited after I had settled my account and have now placed me in this predicament. All I want MY money which you took from my account without my permission. I will then consider taking my business elsewhere.