Volume button cable is torn. Silent switch, volume buttons don’t work.

Try buying a new volume button ribbon cable off ebay or amazon, there should be a ifixit manual on how to replace the volume ribbon cable. If you have warranty, then book a appointment with genius bar at ur local apple store, or get it repaired by 3rd party, just go to the mall and find a phone repair shop, and have it repaired, thats all i can say, i hope you the best.