Account handed over after payment arrangement was done

I visited the gugulethu municipal office in 2018 for a payment arrangement and was told to make a 10% payment before the arrangement can be approved of which I immediately did and i followed thu on the arrangements. To my surprise a month later a received an sms stating that my account has been handed over to the attorneys however i still continued with payments as per arrangement and now thus far I have paid R30 000 towards the bill and have less that R3000 outstanding. when i contacted the contact centre to query the judgement they were not able to provide details as to the attorneys that the account was handed to and the reason why the account was handed over after I has already visited the offices and made a payment arrangement. I order for the judgement o be removed i have been told i need to make an upfront payment of R1500 . Why was the account handed over after i had visited your offices and already made payments?