Bad service from the personal loans department

I paid my personal loan account and was debited twice again after that without my consent, on Monday I spent the whole day on the phone being transferred from pillar to post and ended up not getting assisted, yesterday morning after waiting for about an hour holding on the phone I eventually spoke to someone and they promised me to refund my account in 24 hours, that 24 hours lapsed this morning at 9am. I am wondering why such a big bank is struggling to get such a small thing right, and why are there so many departments that one must go through on the phone being transferred while no one is even willing to assist. I need my money back urgently my children do not have food.