Dishonesty and Misrepresentation

I received a settlement offer from this company, who are debt collectors for the SABC on payment of TV Licences, they offered me a final settlement of R795 on my Tv license which i paid. A day after i paid i still received sms with demand for payment, i sent them a whatsapp on their whatsapp nr *** with a snapshop of the payment as well as an email to *** advising of payment. The messages stopped thereafter( so I assumed that the necessary recons were done and my account brought up to date). To my surprise when trying to buy a TV today, I am told my TV license account is in arrears. I will not be conned in this manner and will not stand for the misrepresentation. I need this to be rectified.