Handed over!!!

Today I received an SMS from ITC saying that Discovery handed me over for an outstanding amount of R450!<br> <br> The most amazing thing is I cancelled my Membership in March 2014. (Because of really bad service). I had approx R 30,000 in my savings portion. I asked Discovery to pay it over to my new Medical Aid. They paid R30,000 into my personal account as well as paying R30,000 to my new Medical Aid.<br> <br> At a huge inconvenience to me I paid back every cent and received a statement with a zero balance. Now almost one year later they hand me over for R450 without any correspondence or notification.<br> <br> Are they allowed to do this?