Bad attitude & unnecessary interest

SABC handed over my tv licence account to MBD Iast year. I made arrangement that they are going to debit for six months. The last month was February of the debit, I was phoned on monday by the MBD saying I owe R336 and why did'nt the debit order went through on march I said it was arranged for six months. I asked where does this R336 comes from because I'm not in arrears I've paid 2014 and 2015 is due at the end of this month or April. She told me its for 2015 I asked her if the tv licence is that amount this year she said its because SABC handed over my account. She gave me the call centre number of SABC and I phoned today before 12 it was not easy to get a consultant. At the end a lady answered and I asked her why am I supposed to pay this amount she said I made debit order and I said it was for 2014 not 2015. We argue and she drop the phone and I'm not clear even now why I have to pay to the lawyers the account that is due on the month end. I still want explanation because I'm not going to pay tv licence with interest when its only due month end. They say all their calls are recorded they must find the rude consultant