When I became lvl 60, I got all my Waterworks gear in 3 tries of the dungeon. I didn't think the odds were that bad. I got the boots on the 1st try, and the hood and cape on the 3rd try. My suggestion would be to keep farming, you'll surely get something in a little bit of time.
Drops in Wizard101 are random, some are luckier than others. I got my Waterworks gear in about two days of farming. Just keep trying and trust me, you will get it.