I saw this and your other posts. Maybe it's just me, but when you buy something online sight unseen, you are entitled to an accurate description of any defects, which sound like you did not get. I'd email the seller these pics and ask them what it is and what to do about it. (Sorry, I do not know). Then post what they say here, so knowledgeable people can verify if it's correctable. These leaves are not likely to magically lose these spots, but as long as new ones are likely to come out healthy, maybe you are OK.

But if I were you, I'd be inclined to ask for a refund if this was not disclosed in the description and especially if the price is not significantly under market - or even if it is but you want a completely healthy looking plant.