Wrongly charged more than double, then a huge fight to get back MY money

I was with Hollard for years. We bought a new vehicle and added it into my policy, no problem there. The problem came when they took more than double the amount off of my account than what was agreed upon.

Luckily I have a fantastic broker who picked this up before the money came off. He contacted Hollard to point out their error, their excuse "we've already submitted that amount to the bank and can't change it now". We asked for an immediate refund and were told we'd get it.... we are now just over 3 weeks down the line and still nothing. My broker inquired again 2 days ago, 7 October. Fun thing is they said they did the refund on 7 October (not immediately like we were promised). Still nothing has reflected on my end, let's just pray we finally get our money back.