I remember this. I graduated in 96 so probably same system.
When I was university there was a kindly old gent who used to administer the paperwork. He advised us to spend the cash on something useful like a computer or invest it in a high interest account, as we'd be paying it back for years. He also explained that we had to put down the name and address of someone who would vouch for us in the future if the SLC lost track of us. I put down my best friend and she put me down.
All you have to say is that you've lost touch, and they will leave you alone.