Denied Boarding - port of entry different from visa issue country [duplicate]

I was supposed to fly from Mumbai to Amsterdam, but because of the denied boarding I couldn’t reach my final destination as planned.

Few days back I did a Europe tour from India. So, I can apply for a visa from the country which is either my first port of entry in this case Netherlands or the longest stay which in this case Poland and therefore, I had applied for my visa from Poland embassy.

Now following is what happened with me.

1. My flight was from Mumbai, India to Amsterdam, Netherlands via Istanbul with Turkish Airlines
2. I travelled from Mumbai to Istanbul (no problem here).
3. When I was boarding to flight Istanbul to Netherlands, airlines officials (the ones who checks the boarding pass before boarding the flight) told me that I could not board the flight because my visa was issued by Poland and I need to go to Poland first. They were denying the longest stay option of the visa. Moreover NONE of the staff of Istanbul airport were able to understand English so I had to go to a lot of problems before I managed to get tickets to Poland and that too with the help of some official through Poland ticketing office, which is beyond Istanbul passport office. The only direct flight available is through polish airways for that day and not with any other airlines.
4. I somehow managed to fly to Poland from Istanbul after lot of struggle at Istanbul airport (without food and water).
5. I did not received my luggage at the Poland airport and had to spent whole night at the Warsaw airport and took a flight to Amsterdam from Warsaw airport next morning.
6. I got my luggage after almost three days of my flight from India at the Amsterdam airport.

I emailed airline for compensation and below is the response "The passenger shall be solely responsible for complying with all laws regulations, orders, demands and travel requirements of countries to be flown from, into or over, and with Carrier's Regulations and instructions. Carrier shall not be liable for any aid or information given by any agent or employee of carrier to any passenger in connection with obtaining necessary documents or visas or complying with such laws, regulations, orders, demands, and requirements, whether given in writing or otherwise; or for the consequences to any passenger resulting from his or her failure to obtain such documents or visas or to comply with such laws, regulations, orders, demands, requirements, rules or instructions.

In light of above information, we are sorry to inform you that we are unable to cover additional costs, such as new tickets for Warsaw arrival and transfer payments, considering document check in Istanbul and denied boarding before TK1953 flight departure."

Is suing the airline only option now? Are they fair in denying the boarding as per their mail?