Discovery threatens to sue for R298

So, I couldn't afford my Discovery medical aid anymore.March 2018 Discovery cancels my medical aid. At the time I had R8000 in MSA savings. I requested them to pay it into my personal bank account - I was told I had to wait 3 months just in case there are late claims from a service provider. So Discovery was earning interest on my R8000 for about 4 months - 2 months ago they start sending me emails that I still owe them R298-00. (Btw Discovery paid the MSA amount less certain deductions if memory serves me right into an account which was frozen and not the nominated account. Discovery refused to reclaim that funds back from FNB and pay it into the account I requested them to pay it into. Now Discovery is threatening via ITC-BA to sue. Stuff you Discovery Health - you had Nearly 4 months to ensure that all claims are paid, You earned interest on my MSA SAVINGS - YOU, DISCOVERY CAN RIGHT OFF R298-00.