front tooth crown

4 years had 2 front tooth crowns. right front tooth was real good, left front tooth has caused pain since day one, been to dentist so many times complaining of pain. still nothing was done dentist said i had trigminal neurogoly after seeing 4 neurolglist back to dentist. pain is every day and crown hurts and feels too big, dentist sad cause of pain, still no medicine . now he want me to see a speclist to se if nerve damage or root canal, no insurance will pay. is the dentist that did crown at fault for not fixing crown when i first complain 4 years ago and no relieve only pain