TV license thievery

Today I received a call from VVM on behalf of SABC tv license indicating I owe a penalty fee for an account I.had made a payment arrangement for. I had honoured my payment agreement, however made the first payment on 20 December when my salary paid out, then when my January salary paid out 23 Jan which completed my agreement. However today I am told I owe a further R70 penalty for paying late(2 days). How is this?, they are trying to aquire money from me unnecessarily as a result of when I paid them. I am disgusted at the fact that they could be this blatantly *******, also how do I control when my salary pays? Everyone was paid early for the festive season, now I'm being threatened to pay this amount... why not chase after the people that own tv's an never pay ?