Nedbank stole my money and refuse to give it back

I bought my property with Nedbank in 2010. Big mistake. Last year, after 7 years, I decided to sell it and move on. Nedbank quoted a settlement in November 2016, and I accepted. It took some time for the sale to go through, eventually going through in May this year (2017). Sometime in at the beginning of 2017 I asked Nedbank to stop debiting my account, as they had received guarantees from lawyers and the purchaser's bank. They refused, and continued debiting me. When the sale went through, they refunded me all the debits since the quoted settlement, as they should. However, when paying out the proceeds of the sale, they paid me R19,000 or thereabouts, short. I spoke to the lawyers, and they pointed me in the direction of Nedbank, who took R19k more than the settlement for themselves. In essence, they took more than even the original price of the property when I bought in 2010. When I query it, they take ages to get back to me. Even then, the consultant I speak to is clueless and cannot answer any questions. I keep explaining the same thing over and over, and he takes ages to get back to me. Nedbank has, thus far, flat out refused to even send me the closing statement of the homeloan account, to prove how much they took from the sale. They are deliberately dragging this matter, hoping it will die a death, when they ******** me out of R19k, and cannot even prove to me by showing me statements. The consultant I spoke to, a Vis Govender, keeps referring me to the refund on the debits as though they gave me my money, when in fact they did not (and he knows it), and refuses to understand me. The refund doesn't even add up into the sale proceeds, as he claims. I need my money back, Nedbank are not trustworthy, they are *******. And yes, I will close my accounts when this matter is settled. Good thing I kept my business account from their greedy claws.