Staffing shortages at a local tax office have prompted a bit of a tit-for-tat between U.S. Rep. Doug Collins, R-Gainesville, and the Internal Revenue Service. The IRS acknowledges that the tax assistance center is understaffed and that’s its caseloads have been exacerbated by the closing of a separate office in Athens. The Gainesville branch, located on Oak Street, is the only location to serve more than 700,000 residents throughout Northeast Georgia’s 9th Congressional District.