Louisiana Revised Statutes Tit. 47, § 818.121. Refund claims

A. Each claim for a refund shall be filed on a form provided by the secretary, shall be supported by the original invoice issued by the dealer, and shall contain all of the following:

B. The purchaser or person who received the delivery of compressed natural gas, liquefied natural gas, or liquefied petroleum gas shall obtain the original invoice from the dealer not later than the thirtieth day after the date the fuel was delivered. If the purchase or delivery of fuel is made through an automated method in which the purchase or delivery is automatically applied to the purchaser's or recipient's account, one invoice may be issued at the time of billing that covers multiple purchases or deliveries made during a thirty-day billing cycle.

C. The secretary may pay a refund to a person other than a school bus driver who files a valid refund claim. After examining the refund claim and before issuing the refund to the dealer, the secretary shall deduct from the amount of the refund the one-third of one percent originally deducted by the dealer pursuant to R.S. 47:818.119.

D. A person who files a claim for a tax refund on compressed natural gas, liquefied natural gas, or liquefied petroleum gas used for a purpose for which a tax refund is not authorized or who files an invoice supporting a refund claim on which the date, figures, or any material information has been falsified or altered shall forfeit his right to the entire amount of the refund claim filed unless the claimant provides satisfactory proof to the secretary that the incorrect refund claim filed was due to a clerical or mathematical calculation error.