Student visa - best place for Portuguese classes (São Paulo)

I've been here a few years now and have come across this story a few times - people arrive in Brazil for a trip, a relationship or a short term job, like it here, and want to stay. But then their visa runs out and they have to leave the country to avoid a fine and avoid staying illegally.

One of the easiest ways to ger around this is to officially start learning Portuguese (at a university or dedicated school) - if the language programme is of a certain duration and intensity, foreigners qualify for a student visa that way.

Does anyone have any tips on which schools/universities are the most supportive during this visa process and also the best value for money in terms of courses? I have been asked this question 3 times in the last month, so I thought it would be nice to hear your collective opinions on this.

Cheerio and thanks for your help!
Roger