(a) Recovery of charges by carrier
All actions at law by carriers for recovery of their lawful charges, or any part thereof, shall be begun within two years from the time the cause of action accrues, and not after.

(b) Recovery of damages
All complaints against carriers for the recovery of damages not based on overcharges shall be filed with the Commission within two years from the time the cause of action accrues, and not after, subject to subsection (d) of this section.

(c) Recovery of overcharges
For recovery of overcharges action at law shall be begun or complaint filed with the Commission against carriers within two years from the time the cause of action accrues, and not after, subject to subsection (d) of this section, except that if claim for the overcharge has been presented in writing to the carrier within the two-year period of limitation said period shall be extended to include two years from the time notice in writing is given by the carrier to the claimant of disallowance of the claim, or any part or parts thereof, specified in the notice.

(d) Extension
If on or before expiration of the period of limitation in subsection (b) or (c) a carrier begins action under subsection (a) for recovery of lawful charges in respect of the same service, or, without beginning action, collects charges in respect of that service, said period of limitation shall be extended to include ninety days from the time such action is begun or such charges are collected by the carrier.

(e) Accrual of cause of action for transmission of message
The cause of action in respect of the transmission of a message shall, for the purposes of this section, be deemed to accrue upon delivery or tender of delivery thereof by the carrier, and not after.

(f) Enforcement petition
A petition for the enforcement of an order of the Commission for the payment of money shall be filed in the district court or the State court within one year from the date of the order, and not after.

(g) "Overcharges" defined
The term "overcharges" as used in this section shall be deemed to mean charges for services in excess of those applicable thereto under the schedules of charges lawfully on file with the Commission.