228.66—Refunds.
Upon termination of any contract, payments in excess of $10 may be refunded, less the costs incurred by the United States, under any of the following conditions:
(a) Payment in excess of value.
If the total payment exceeds the value of the mineral material removed, unless it is the minimum annual payment in lieu of production;
(b) Insufficiency of material.
If insufficient mineral material existed in the sale area to provide the quantity of material estimated to have been available;
(c) Termination.
(1)
If the contract is terminated by the authorized officer for reasons which are beyond the purchaser's control; or
(2)
If the contract is terminated by mutual agreement. This refund provision is not a warranty that a specific quantity of material exists in the sale area.