When I first set up my 29 gall, I did just that. I bought 2 non aquatic plants in the tube because I didn't read the fine print on the tube. It does say
Its a filtration system.
either way i still refuse to buy fish from them.but you are right.it was my fault.i guess...i could give them a second chance.
the biggest tank i myself would put a betta in would be a 55 gallon.and i may know w alot of stuff about fish but i truly dont know what an over flow