"Can't get appointment"

The process of booking an appointment puts me off to see my GP. It's very difficult to reach them over the phone. You can't just take a day off from work to call your GP! I've called 20/30 times in a span of 30/35 minutes between 8am to 8.30 on a weekday but couldn't get through. This is really frustrating. There has been incidence in the past where I wanted to discuss a symptom of some kind but after trying couple of days, had to give up. My worry is because it puts people off, small issues gets swept under the carpet which might cause bigger health problems in the future. I've recently registered for the NHS app for ease of appointment. Even that app is useless! It required to provide all sort of ID and Documents which we produced. But in the last 24 hours, every time I'm trying to book an appointment it's saying it is not available.