I used to work at Extreme English in Arequipa and my experience was terrific!!!! Students (not everyone but 80%) were so nice and worked hard too. I got the material that I needed on time and every time I had a teaching problem or anything related, the owner and manager always were in a good frame of mind to help .Maybe, my friend, you didn't have the chance to know or share time with him or the people to work or study in the school.
The only thing I can really agree with you in is that at Extreme English Institute you have the best pay around the city because no English school pays you as this one does. In fact, I'm coming back there this January for 6 more months and if possible, I wanna stay for a complete year.