Why must i pay a written off account

i am so amazed at the level of how even to this day so institutions are taking people for a ride , I have a situation were MBD is expecting me to pay off a written off account that was last in 2005 and they have been hounding me about it each and every month they call me expecting me to pay them I anf the amount has gone from R5000 to 9500 and it keep on increasing how is it this legal in any way and why when the minister said things like this should not ne happening but MBD still has the never to suck up money out of me knowing how hard some if us are struggling ,it is so disgusting for them to try and get the little that we are trying to make in making us pay for this ******* ,I want them to take my matter to court and so that a legal entity can give me information as to why is it that they are getting away with things like this it is so ridiculous