Nedbank harrassing me

Opened a Nedbank account a while ago. Week after opening my account almost R1700 was taken out of my account. After enquering at the bank they informed me that they took it for a loan that I had in 2005. I told Nedbank that I never had a loan with them and that my id book got lost in that period. The lady from Nedbank told me that she will give my money back if I made arrangements to pay the money back. I then told her how must I admitt to something if I did not borrow the money. I also rep**** to her in a email to say that they must stop contacting and threatning me. The lady also numerous times tried to trick me into saying that I borrowed the money. After that I started receiving sms'es saying that I phoned them making arrangements to pay the money back at R50 per month. I never phoned them making any arrangements because I didnt borrow the money. Now sometimes twice a day I am receiving threatning sms'es saying they are going to come to my house to take moveable assets and so on. How in the world can you come after 13 years and claim that I owe you money if I never borrowed any. They are harrassing me and I have already seen a lawyer that has advised me that he is going to take it to the ombudsman if they do not stop with threatning me. I had to close my account in worry that they will just keep on taking money that is not theirs. This is the worst experience I ever had with a bank.