Air India — rejected on andaman island

I flew with air india from kolkata to port blair and several of your staff checked my visa and assured me it's fine. As i flew in port blair i was immediately approached by the staff there and forced to buy a super expensive flight 18.000 rupies to go straight back to kolkata. Now i ask back the damage of money (Flight and hotel) which i suffered from due to your airlines mistake. Please inform me how you want to handle this issue. I always flew air india and i hope you will be fair to a long term customer. Best regards.