i would say internship student is consider cheap labor in the company. when i was i did my intern few years ago in one of the manufacturing company, the pay was shit. yes, there didn't have any benefit.. even thought not any paid holiday. i think it's a little bit unfair.. but student doesn't have any option and dare not to argue too much as afraid of the manager will terminate the contract anytime. why? because he/she just want to get some commercial experience before graduate.
but the bright side is when you have graduate from your degree, it will helps you a lot when you are applying job. at least you can stand out from the crowd when you are applying job.