OP, notice the name of the R8 bundle: it has a number II in it (I don't know why the random Roman numeral, but whatever).
On my main account, where I have the characters at R7 or higher, I only see Bundle 2 for R8 (because I don't have all of the included characters at R8). I didn't buy the first one, I've had BKM on this account for a long time.
On the alt, which doesn't have BKM, I only see Bundle 1, the one with R7 characters.
Therefore:
-> account doesn't have all bundle characters at R7: offer Bundle 1
-> account has all characters at R7, but not R8: offer Bundle 2
-> account has all bundle characters at R8: presumably doesn't show Bundle 2; maybe there's a Bundle 3 that sells the characters at R9 (tbh I would be surprised if Bundle 3 doesn't exist)
You didn't have the characters at R7, store showed you Bundle 1. You bought Bundle 1 and now check the condition for Bundle 2, so the store shows you Bundle 2.
It's not that Bundle 2 showed up later. Bundle 2 was released at the same time as Bundle 1, but your account didn't unlock it in the store until you bought Bundle 1.
You didn't get scammed. It's just CG being extremely predatory with the pricing. But again, there's no scam here. You bought one thing and the store just automatically queued up the next offer for you.