(a) Every bank shall obtain and maintain deposit insurance satisfactory to the department; provided, however, that banks which have had their deposit insurance withdrawn or canceled may, in the discretion of the department, continue to accept deposits; provided, further, such banks shall within six months after such withdrawal or cancellation of insurance obtain deposit insurance, satisfactory to the department, written by an insurance company authorized to transact business in this state or by the Federal Deposit Insurance Corporation. The department may, in its discretion, for cause shown, extend the time limitation in which deposit insurance must be obtained.

(b) Deposit insurance required to be obtained in subsection (a) of this Code section need not be in excess of amounts insured by the Federal Deposit Insurance Corporation at the time the insurance is obtained; but wherever the insurance coverage is, in the opinion of the department, less than amounts insured by the Federal Deposit Insurance Corporation, the bank shall be required to post at a conspicuous place near the entrance of such bank a sign in boldface print, in letters at least four inches high, which states "Deposits Not Insured" or "Deposits Insured Up To (insert amount of deposit insurance)." Such wording shall also follow the name of the bank wherever it is written or printed and shall be posted in writing which is easily legible in letters at least one inch high at each window or desk receiving deposits.