That is an ACF, thats fer sure.
As for housing it with a betta...hmmmm...betta will probably pick on him, and vice versa.
Clawed frogs will try to eat anything, even if its too big.
When I first got mine, he was 'bout the size of a "ADF" and he treid to eat my goldies that were 4-6 inches long.
You can imagine what that looked like.
I would see my goldie's come whipping from the back of the tank with this tiny lil frog clamped onto they're tails.
LOL
Looked like the frog was having more fun than actually trying to eat em.
But anyways, I would bring it back and exchange it or house it in a bigger tank by itself.