TaxJar Sales Tax Automation

Support can't tell me why the total sales in one county do not equal the sum of sales in three cities located within that county. I'm just getting cut and paste replies that suggest I should inquire with my state's DOR. My return is being flatly rejected because of their faulty calculations. How could the state have an answer for Taxjar's unacceptable numbers? They've basically shrugged their shoulders literally telling me that Taxjar uses 'lots of tax logic'.