ppl at work don't take me seriously because of my age and looks WHAT TO DO , HELP?

i just graduated from college with degree in finance and found this awesome job ......but no one in the office takes me seriously, even my boss , he says he likes me around because i am cute and funny female thats all, but he would never trust me with money,,,,,,ppl in the office tease me, make fun of me, stare at me, laugh at me .......first i tried to smile back and laugh also, tell them a joke on how dumb i am so that they would like me even more, but now , since 3 mounths pasted, i realized i havent' done much ! i've never had a client! i've never had a case to handle of an excisting client!! its not funny anymore, what should i do???