****med and ****** by Standard Bank

I started using a Standard Bank Student Account in 2004 then in 2008 I went to close it as I was no longer a Student, I went to Jabulani mall and tried to open an account but I didn't qualify for their accounts due to my salary, I then asked them to close the student account I had with them, which they said it's not issue, if I don't use it it will automatically be closed but I insisted they close it and they said they will do so. Today I owe standard bank around R20 000 which I have no idea how, in 2009 they took my provident fund amounting to R3000 or more but to date I still get smses and calls saying I owe them. Which I personally believe they owe me