Account balance is 0 but disconnect Dstv

On Saturday when I wanted to pay online, the system showed 0.00 outstanding, so I screenshot that and didnt pay my Dstv, today they decided to disconnect it due to non payment, when I called the lady told me that she also sees the same on her side that I have 0 balance outstanding and she will log a complaint and someone from DSTV will call me, now I recieved an SMS to make payment with reconnection fee, really where is the mistake here