Wrongful billing

I reconnected my service in Dec 2015 because we had moved and was not stationed for 9 months. I talked to Jabulani Radebe at Multichoice in Jhb on the 17/18 Dec 2015 and was advised by him to make a payment of R252.00 (pro-rata for Dec) for reconnection. This was done immediately, although my service only activated on the 20th of Dec. Now almost 2 years later they have suspended my PVR function, because according to them I still owe R172.50, because apparently I was not billed correct even if I only received access for 10days in Dec 2015. Please can someone advise?