PROBABLE NERVE DAMAGE. What to do next?

An oral surgeon, after being asked by a dentist, extracted my lower left wisdom tooth 12 days ago by cutting the bone and since 4-5 days after the surgery when the pain reduced significantly and I could start focusing on feeling things inside my mouth, I realised that my left half of tongue was completely numb. Moreover the left tongue always feels like it has got burnt in something hot like hot tea/coffee and gives me tickling sensation all the time. I think the oral surgeon might have damaged some nerve. I am very scared and dead angry at the same time. If the surgeon was not capable enough of performing a surgery in a way an expert should, he should have simply denied the surgery rather than performing it for 2500 and putting my life at a great risk. I was also not given any idea about post-surgical risks & complications, as I might have changed my mind about extraction, thereby denying them a golden opportunity to make some easy money. Please help me by suggesting what to do next