Complaint Letter

I am writing to complain about the leisure centre 2K and the new class for advanced swimmers particulary.
First of all, when I attended the class it started late at 6.20 p.m. I was sure it is not worth of complaining, but when it happened again next time, I am sure, you will agree, it is not tolerable.
Secondly, in your advertisement, it was mentioned that the class is provided with experienced instructors. But when I asked to one of the instructors what would be the daily exercises to improve my swimming and technique, he could not give me a proper answer!…