I would ask her out one more time, if she doesn't accept, move on. Generally you want to ask a girl out 2-3 times. If a girl says no to me 2 or 3 times, asking her out again, is usually just wasting my time. I'd rather look for someone else.
Try to expand your social circle. Join a local meetup group. Hang out with cool people. Have cute friends that you don't date. That'll really expand your circle a lot.