They are selling as "mahogany" something that can most likely reasonably be called "mahogany," and which they most likely purchased as "mahogany."
It's loose. It's vague. It's imprecise. It's broad and general. But for that very reason, it's not lying, it's not deception, and it's not fraud. They use the loose description on purpose, so they can use a wide variety of woods without being fraudulent. They wouldn't want to spec "Agathis" on something, and then have an unexpected problem with their Agathis wood supply.
SO MANY types of low end Asian-Pacific lumber are sold as "mahogany." The factory itself probably buys their lumber for such guitars as "mahogany," from their lumber distributors, and don't know exactly what they are going to get, other than that it's something that the distributor is selling as "mahogany." If they knew exactly what they were getting and using for an entire line, they'd probably say so. "Agathis" can be referred to as mahogany. But sometimes it is referred to as Agathis. The difference? I'd say it's the known consistency of supply.
In other words, it makes sense that the generality would be to prevent themselves from lying when using a wood supply that is by its nature inconsistent. Generality to cover your ass is not lying, deception, or fraud. It's knowing that you can't be specific, and stating as much.
At any rate, this conversation really has nowhere to go until the OP sends a sample of the wood in to a lab for analysis. We have an out of focus photo with the wood obscured by coloring, and we are just trusting the OP's statement that the bass was supposed to have a mahogany body, based on serial number. We don't know the original retailer, or have access to the original description. And we don't have a proven timeline of when the manufacturer changed the published specs.
For me, the bottom line is that if the OP thinks that fraud was committed, then by all means, report it to the appropriate authorities and see what happens with the case...and get ready to be laughed at.
Nobody got screwed here. Probably not even when the bass was new, and certainly not if bought on the used market.
You have to be smart enough to read through the noise made by marketing machines.