Payment

I payed my dstv this month and I was told that I had to pay 181 that was outstanding last month and I know I payed my dstv last month and I was never given a grace period and I don't know why they didn't switch it off cuz I know they do that or if you didn't pay the whole amount they don't open it at all. So I don't understand why they who leave it pay the whole money and they tell me I have an outstanding amount. And I have been a dstv customer for a very long time.