BAD CUSTOMER SERVICE

I am so disappointed in Absa and the person John Van Zyl who is representing ABSA, calling us and saying that our vehicle of almost 6 years is in arrears with just over R5000. We called and emailed and whatsapp him to arrange to pay this off. We offered for this month R500 but he declined the offer and say if we dont pay what he says Absa is going to sell my vehicle. Can they do that ? Its not that we are not paying, we are paying our Instalment every month. I need help urgently as How can a representative from ABSA threaten us like that.