My conure's wings won't grow back

My conure parrot got his wings cut at the canary farm last June (over 4 months ago) just like I do every summer to assure he doesn't get loose with the doors being open all the time. He is usually able to coast again after a month and fly again normally after two months. He is still not able to even coast. He tries to fly and plummits to the ground. He is getting hurt making his feathers fall out and his wing to bleed. Why can't my bird fly again? Is this perminant?