Unhappy client

I'm very with Nedbank, firstly they go to my account and take my money which they were not suppose to and of which they also admit that it was an error on their side but now they are making it a struggle for me to get my money back. I put through my query last week Wednesday I was told everything will be sorted in 48hrs but that never happened, I followed up on Monday and was told to wait 24hrs, only on Tuesday was I then told to go to the branch. At this point I'm ****ed. I went to the branch and they are also giving me issues. This is very bad service