Reputable Vietnamese Language School

Hello,

I've recently moved to Ho Chi Minh from Singapore and I'm keen to pick up the Vietnamese language. However, I'm a tad overwhelmed by the sheer number of Vietnamese language schools available. Especially when I can't seem to find reviews that vouch for the quality of said schools.

Has anyone attended a Vietnamese language school (no private tutors or language-swapping friendships please) that they highly recommend? I'm looking to attend a class (group learning settings preferred) that issues a legitimate certificate. I'll very much like to include learning the Vietnamese language to my list of professional skills and thus, would like to acquire a legitimate cert to back it up.

Thanks in advance!