Phoning now about payment only due on the 19th

I have never missed a payment. Your call centre phoned me just now about paying. Why?<br> I feel this is harassment. I make my payments on the 2nd of every month and according to your system it was only due on the 19th of December. I find this unacceptable. Furthermore, your agent phoned and asked about my 'Absa' card - I do not have an Absa card and as such was immediately on the back foot with all the ***** going on.