Graduate job is NOT guaranteed! Even after training (12 weeks unpaid although free accommodation which is a good standard) job is not guaranteed. If they can't find anything for you they will say you are not good enough and let you go.
Pay is considerably below par for this industry and there are few benefits. Some clients work you considerably overtime (although this is not with everyone) and will send you back just like that if you complain and will most likely will be let go after that.