The reason why I asked about the money is that I was trying to determine if small claims court was a possibility for your circumstances -- because in small claims court, you don't need to actually plead a specific cause of action (e.g., unjust enrichment).
Legally, the tort of "unjust enrichment" doesn't exist under California law. "Unjust enrichment is not a cause of action, ... or even a remedy, but rather `"`a general principle, underlying various legal doctrines and remedies'" .... [Citation.] It is synonymous with restitution. [Citation.]' [Citation.]" (McBride v. Boughton (2004) 123 Cal.App.4th 379, 387 [20 Cal.Rptr.3d 115].)
So, when you ask the question about how to file for unjust enrichment in California, I suspect that you may have previously received legal advice which is simply incorrect. The correct cause of action is either "quantum meruit" (i.e., the value of services rendered), or "quasi contract" (i.e., a contract which for some reason is unenforceable, or circumstances under which no contract was ever contemplated, but where a person has received an unjust benefit at another's expense, and is thus obligated to to restore that benefit to the party from which it was received).
If this is a situation where a GC hired you to perform services, you performed those services, and you haven't been paid, and there is some agreed upon evidence of the value of those services (e.g, a purchase order -- or an invoice from you to the GC which has not been rejected), then that would be a straight breach of contract claim. If there is no evidence to value your services, but you performed services in expectation of compensation, then your claim is for quantum meruit.
I'm really not trying to be difficult here, but I routinely work with contractors -- and there are always the sort of problems you describe -- because, and especially with commercial projects -- the parties simply don't spend any time to put the deal into writing -- which creates the opportunity for a dispute.
That said, I can't tell you how to plead a case to recover the value of your services in this forum -- that would be malpractice -- because it's way too complicated to just tell you to file some particular pleading (outside of small claims court). I'd need to review all of the facts and evidence. Which, of course, means paying for legal services -- something which I'm fairly sure is the reason why you came to Justanswer -- i.e., to avoid paying a lawyer to try to resolve this matter.
Anyway, based upon what you've disclosed here, I doubt that you will be able to collect from the GC outside of small claims court (which has a limit of $10,000 damages, unless you're a corporation or LLC, in which case it's only $5,000.
If small claims works for you -- great!
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