Yes, call the manager and complain about the one you had the appointment with. Let them know your appointment time and what time you left. All they have to do is look in the appointment book to see the whole scope of the problem.
I'm going to guess since that turtle's ancestors lived outside without lights for thousands of years, he should be ok. Set up his habitat like it would be naturally and he will be happy.
Nope potatoes are starchy, when eaten the convert to sugars, so you will gain weight if all you eat is potatoes... it will probably mess up your blood sugar levels too.