Gym... lots of cardio... but getting bigger thighs! Whats going on?

I have been to the gym about 10 times the past month. I used the rowing machine for 20 minutes, elliptical on low resistance for ten minutes and running for 40 minutes. Instead of slimming down i have gained muscle and the reason i have been going to the gym was to tone down and make everything smaller.
This is really annoying and i dont know what i am doing wrong. I won't have a gym for the next 3 months so I will just be jogging. I hope i dont get bulky from that.
I also do about 50 sumo squats with no weights per day and lunges.
Gym... lots of cardio... but getting bigger thighs! Whats going on?
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