Betta and Tetra Glowfish

Went to get a betta today for my 10 gallon tank. I also got 3 tetra Glowfish. The lady at the LFS said it should be fine. I put them all together now and I don't think the tetras look very happy. I've been doing some reading and everything I've read said the tetras should be in schools of 6 or more and I would need a bigger tank. Should I take the tetras back?

 

Yes. They do need a bigger tank and to be in a group of 6+. 20 gal long minimum for a betta in a community tank and there's not much overlap between bettas and skirt tetra.

 

If you are able to take then back, then yes. They should be in a larger tank and larger groups.
ALSO, Betta's ( especially males ) do not tolerate MOST tank mates well. They are kept alone for this reason. Unless you have a way out for the fish, its best NOT to keep anything with the Betta. Even snails and shrimp are risky and should be avoided.

I had a Mystery snail with a Betta for about 6 months - seemed fine until one day the betta started attacking the snail for no apparent reason. It happens. Luckily I had another tank running so that was that.

 

I returned the tetras and got 2 African dwarf frogs. The betta hasn't noticed them yet so we will see how it goes

 

That also might not be a good idea. The betta can easily outcompete the ADFs for food, and the ADFs might bite the betta's long fins.