Where can we find transportation assistance for Mom's chemotherapy?

My mother has cancer, is on a limited income, and she is receiving treatment at UCI Medical in Orange, CA. The problem is, is that she lives in Murrieta. Her primary physician has his office in Temecula. She is able to drive to her primary physician and to the lab for blood tests and scans, however, the 60 miles to UCI is too far for her to drive. She uses SCAN as her provider, and they furnish her 15 round trip rides per year. But, since she is getting chemotherapy, she is running out of rides. Is there an agency available that will drive her into Orange County for free or at least at a reasonable rate for her visits? All we have been able to find are rides for over $200. Also note that she has no family residing in her area.