Except as may be expressly authorized by these rules or by statute, no other forms of prehearing discovery shall be authorized or permitted including, but not limited to the following: interrogatories; requests for production of documents and things; requests for physical or mental examination; and requests for admission.
Ga. Comp. R. & Regs. R. 20-14-.19
O.C.G.A. Secs. 43-3-8, 43-3-20, 43-3-21, 43-3-22, 43-3-23, 43-3-24, 43-3-28.