Pegasus Airlines Baggage Mishandling and Hidden Fees Ruined My Montenegro Trip

I purchased a plane ticket from Pegasus Airlines for Montenegro. On the return journey, they took my luggage under the plane without informing me beforehand that I would have to pay extra. After stating that I could choose, they charged me 75 euros. When I requested my luggage back, they claimed it was my right to have it with me, yet they did not return it. They announced that the plane had arrived, but it was delayed, and the plane had still not arrived.

There isn't a single responsible person from Pegasus Airlines. Upon my return in Ankara, I spoke with officials who assured me they would refund the fee, but they asked me to apply online. I've been applying repeatedly, but my applications are consistently rejected.