They are pocket pickers; meaning they'll do extra work that you clearly did not ask for and charge you an extra charge without you having a say in it.
My experience: I went in and clearly stated that i just wanted my split ends trimmed. The lady who attended me not only cut off more than i wanted but she styled my hair and charged me $5 extra dollars for it. I was charged $20 when a regular haircut costs $15. I thought this place was going to be cheap, i now regret not going to great clips in the first place where they only charge you $10 for trimming of split ends.