I work at a hair salon making minimum wage. My company has training classes on off days and some work days that are unpaid. My managers have said that they are mandatory and essential to the job, but the handbook says they are optional (I’m assuming to get out of paying us.) I missed one class out of maybe 15 this year because I had an appointment I couldn’t move. My boss and the owner of the company said it shows I don’t take my job seriously and I shouldn’t expect my previously promised promotion. Is this allowed?