Business visa without Degree for Teachers?

As the name mention, yes it's a Business Visa - not an employment visa. To obtain employment visa, you should possess an employment contract and other legal documents!

What you are trying to acquire is a work permit and temporary residence card, not a business visa. B3 (business visa) is easily obtained, but it does not entitle you to live and work here.

The BA or equivalent is just that, the equivalent is 5 years or more experience (with references and\or industry qualifications for non teachers)

If you are studying here, then you can get a student visa, this will alleviate your worries in not leaving the country(or doing the visa runs, but does not allow you work legally.

I wasn't aware Vietnam has "Business" visas. You either get a tourist visa, and get it extended every 3 months, occasionally having to leave VN to get it renewed (the Cambodia run), OR your employer gets you a work permit which allows you to get a 3-year temporary residence card.

The 3-month visa IS the business visa, as far as I know. That's the one that was given to me when I applied for my visa, I think because the 3-month tourist one has been discontinued. The Cambodia run is also becoming a thing of the past I hear because the authorities are starting to clamp down after two re-entries.

The work permit has also been slashed to just two years with the new measures enacted last month.

There is a tourist visa (class C) that is valid for three months but in practice they issue a business one instead (B3 to be precise). No requirements to be fulfilled, you get the same one whether you hold a PhD or barely finished grammar school. Same goes for most teaching positions, sadly.