Affordable urinary tract cat food.

My 8 year old male cat has a urinary tract infection. He is on a second round of antibiotics. This is the first time he has had a UTI. The vet prescribed Hills Urinary Care C/D dry food. My cat will not eat this food. I mixed it in with his old food, tried adding water/broth to it. He didn't like the Hills canned food either.He usually eats Rachel Ray dry and sheba wet.It has been 17 days since his first visit to vet for this problem. He has been back twice since. I need help finding a urinary food he will enjoy eating.