I had a professional plumber out today. He spent about 3 hours trying to unclog my kitchen sink. Finally he said there's something wrong with the drain because he can't get it fixed. So here I am with no working sink and I'm not sure what to do now. The company I am working with has offered to bring a camera and have a look around the drain pipes.
Is there anything I can do on my own to try and fix my problem? Why couldn't a professional fix it?