My first was breech she wouldn't turn and was sitting on top of my pelvis the whole pregnancy and wouldn't turn for the doctor. She was a c section. This time my little girl was breech and at about 32-36 weeks or so the dr told me to get on my hands and knees then go down until your face and shoulders are flat on the bed or floor for 10 min at a time, he suggested after eating or when you feel baby moving. I did it whenever she felt active a few times a day. I got an ultrasound and kept an idea of where she was so i could put pressure next to her head and encourage her to flip. It worked twice as she flipped a week after i got her head down. She is staying down now. The position helps open the canal and get the baby more space to flip naturally... best of luck!
Did you have an epidural while he tried to turn her? Tgat relaxes the belly muscles and can make the procedure more effective. Also, try looking in your area for another doctor who would try again. Not all doctors have a lot of experience with external cephaluc version; see if you can find someone with a reputation for success. I'm in an FB group for breech moms, and a lady on there just had a successful version at 39+ weeks, when a previous one at 38 weeks had failed.
I've heard crawling on hands and knees helps them turn on their own! It's worth a try