State of VA Non Resident Refund

[Helper_789]

My son is a college student and a GA resident. He worked as an intern in State of VA last summer. VA state taxes were withheld. We filed Form 763-S in State of Virginia to get his refund and GA Form 500 to report income but no taxes were due. VA is not refunding his withholding stating that he did not pay taxes in GA. There were no taxes due in the state of GA but the income was reported. I need help in getting his refund. All taxes were completed using Turbo Tax. 

[Helper_789]

An recommendations for getting the VA taxes refunded? Do they have a right to keep the money?