Account settled am I being ****med by ABSA

In October 2020 I settled my Vehicle Finance with ABSA,. I received a Settlement Letter confirming settlement. I also received a Phone call from ABSA asking me to come and collect my NATIS documents from my nearest ABSA Branch, confirming that I have settled my account and my vehicle is in my name. Almost one year later on the 18th of September I received an SMS and email from a Vusumuzi Sambo (Collections Officer) demanding a payment of R6690. I am utterly gobsmacked. This account was settled a year ago. I have a been a loyal and good customer to ABSA for over 15 years and this is how I am treated? What in the world is happening at ABSA? Is this some sort of ****? Why am i being hounded for a R7000 that came from nowhere? I am very very disappointed ABSA...