Legal Question in Consumer Law in California

Tell them they either give you the deal, or you'll move.

Given the huge vacancy rate for business space, play hardball. Tell the landlord to offer you the new deal. If they refuse, move.

You'd have to show a lawyer the exact wording to know if you have any legal rights, but given the low rentals out there, this is a golden opportunity for you.

I'm rather surprised that these other attorneys don't seem to think that moving a business is any big deal. Leaves me to wonder if they have ever had more than a desk and a phone to call their office. In any case, if you can credibly threaten to move, then it's good advice. Otherwise, you are probably out of luck. There is a large body of rather old law that says that promotional advertising, even if very specific, is still only an invitation to make an offer to contract, not an offer that if accepted creates a binding contract. Therefore, from a legal standpoint, your landlord is free to say, "Ooops, no, even though we didn't say so, we are only willing to make this deal with new tenants."