Unjustified Enrichment

We purchased a property and made enquiries on adjustment charges of over R2,000 for waste management and rate adjustments whilst we settled all fees with the previous owner, therefor knowing that there's was nothing outstanding. If there were to be an adjustment it could have only been for 11 days, since the property was registered on 19 June, but I have made several attempts to get a valid explanation from City of Tshwane without any joy. Customercare keeps on responding fees for adjustment from registration date, but it is impossible to be that much and if this practice is app**** to all new buyers, they are generating income at the expense of property owners and double billing by charging the funds to the old and new owners.