Georgia Senate budget writers approved an $18.3 billion state budget Monday after making changes in the spending plan to improve customer service and target tax cheats. The Senate Appropriations Committee added $22.6 million to the Department of Revenue’s fiscal 2012 budget and much smaller amounts to the Secretary of State’s office and Department of Driver Services.

While $1.2 million of the revenue department funds added by the Senate would go toward its Customer Service Call Center, the vast majority of added spending on the tax agency would pay to hire more investigators and auditors.

Sen. Jack Hill said the influx of auditors the department hired last year has helped generate more than $46 million in additional tax collections during this fiscal year, above the agency’s projections.

The Senate found the additional customer service and tax compliance money despite a $24 million interest payment the state owes on a federal loan to cover an unemployment trust fund shortfall that has ballooned to more than $600 million.

The payment, which is due in September, was not part of the equation when the House of Representatives adopted its version of Gov. Nathan Deal’s budget request earlier this month.

Hill said $18 million of the payment would come from the governor’s emergency fund.

The Senate sided with a decision by the House to restore half of Deal’s proposed 1 percent cut in Medicaid reimbursements to Georgia doctors. Physicians groups have been fighting the governor’s proposed reduction as potentially devastating to health-care access, particularly in rural Georgia.

Senators added about $50 million to the bond package approved by the House, bringing the list of projects to be funded through borrowing to nearly $700 million.

While siding with the House on a $5 million bond for a new parking deck at the Georgia World Congress Center, the Senate committee removed from the budget $3 million in bond funding for the planned Gwinnett Technical College campus in Johns Creek.