I sent in a payment for the amount that was stated on my tax bill but yet I received a receipt showing there are still taxes owing. Why?

If there were arrears owing on the tax statement, then the tax amount due would change each month because of the monthly penalty charge.

Also, if supplemental property taxes were issued after the general property tax amounts were calculated and printed, this would not be reflective in the amount shown on the property tax bill. Supplemental taxes are due later in the year, and the supplemental tax bills are sent separately from the general tax bills.