A letter of complain

In the advertisement, you say ONLY native teachers, but when I study, there are so many Vietnamese teachers teaching English for students. The advertisement said "NO more than twenty students per class". That's not true. More than thirty students in a class. It's awful! And in the advertisement you say free books and cassette tapes but I had to pay them, it's not cheap. Every classroom doesn't have air-conditioner, it's was fans instead. And the class has began at 5:45 pm and finished at 8pm. Study time less than the advertisement said. I was really disappointed!