hi,
Ok some advice i'll give you that i think could help are .. if you lift then what type of lifting do you do .. which exercises .. if its definition you want to be achieving then i suggest you try doing lifts that start to build a good physical frame for example squats , dead lifts , leg press and leg extensions , these are all very very good
weight exercises for your lower body and after a while you will soon start to notice some definition. As for the reps, i think you are doing sufficient sets. As far as dieting is concerned try eating as much as a balanced diet as you can cutting down on the
saturated fat snacks, you might want to see a doc for help with carb / fat etc balancing. But If you keep doing your cardio coupled with these lifts then unless you don stick it out , you should deffinitly see the fat come off and get some shape in there! ... i wouldnt use supplements just yet , try all you can first and then if nothing still seems to be happening start to investigate them best to go natural first though and work the fat off with hard work
hope this was help , cheers