Legal Question in Business Law in California

You should be reimbursed for your expenses, absent any agreement that limited the time in which to submit them.

I agree with Mr. Cohen. Unless you and your client agreed otherwise, the terms of the client's contract with the oil company do not control your relationship with the client. If it never notified you of a 60-day limit, it can't enforce that limit against you.

Bring your demand on the company, and if not paid, bring a claim in the state and locale of the company. If that is SoCal, feel free to contact me for legal help.

First you need to determine where you can bring an action to determine what rights you have. Places for jurisdiction where contract was signed, where defendant has headquarters or principal place of business, and where work was preformed. Assuming you can get jurisdiction in California then the question is who did you have the contract with? If it was with the 3P then demand the money from them. If it was directly with company then you should have reviewed the contract before you signed it and you would be bound by its terms.