(f) Government Transportation.—
This section applies to transportation for the United States Government. The time limitations under this section are extended, as related to transportation for or on behalf of the United States Government, for 3 years from the date of—
(1) payment of the rate for the transportation or service involved,
(2) subsequent refund for overpayment of that rate, or
(3) deduction made under section 3726 of title 31,