about work i quit

in this time of financial concern i quit my job with no regards to another . i worked for a large national company in the uk but i saw myself being used ie i was doing the work of 3 people but getting paid just as one. this went on for months and i pointed this out to my superiors but no answers from them. it festerd in my mind so i quit because there was no extra help. was i stupid in doing this . i dont think so why should other people have it easy and i know that they do as i was told by other employees in the same job as me.