My cat's ringworm not getting better. Should I change vet?

My question is in the above title? My elderly cat got ringworm in June. It was never officially diagnosed. But her ears started to get bald and I, on my back,got a red skin patch that my doc said was ringworm. So the vet put my cat on Diflucan, on a doasge of a week on/week off over 3 cycles, so took 6 weeks. Her ears healed and all was fine. Until back it came at the end of September. The vet put her back on Diflucan, this time continuously for three weeks.But though he examined her and said it definitely looked like ringworm, he didn't do a test. So it was never conclusively confirmed. This time, with the vet's approval,I ordered lime sulpher shampoo on Amazon and gave her the baths. Almost 4 weeks on, ears still bald, not sore, but as bald as before she started oral meds. All the usual sanitising going on. Cat fine otherwise and not even bothered by her bald ears.

I'm at my wits end and wondering should I change vet? To provide context, her usual vet that she has had her entire life, retired this year and sold the practice to some big group. While my cat is still registered at this practice, I get the impression that the vets there aren't that bothered nowadays.

So how do I go about getting a new vet for a poor little elderly cat in a suspected ringworm flare up? Hugely appreciate any input on this one, thanks so much.