Unfair and ridiculous interest rates and charges on TV licenses

Good day. I have paid my TV license in August last year for R527. Last week I received a notification that I now owe the SaBC R980 rand after settling my account last year. In requesting how they got to this amount they indicated that it us areas on my account. This really unfair, since they confirmed that the license annually is R270 per year. I am still a very discipline citizen paying my account while there are so many unlicensed users outside. I Don't understand how you could double the interest amount from R527 for last year to almost double thd amount in less than a year. This us a real rip of

Regards