Standard bank Home loan

I had a home loan with standard bank and i paid it off in 2012, I then went into the branch to request my title deed and I was given some document and I thought that was my title deed ,in 2017 home loan called me to tell me that I owe them to my surprise because I paid if off. I really feel that standard bank is taking advantage of people that don't know anything. It was my first home loan and I don't know the process that follows after you pay off your home loan. I'm really not willing to pay this amount ,because no one had the decency to call me and explain the steps to follow ot give options in what to do when the loan is paid off. I really feel this is happening because I'm a black person who is clueless. Standard has failed me as my bank. All this years I thought I had my title deed with me to my surprise that was not the case.