Turkish Airlines Cancelled My Flight and Provided Lack of Alternatives

I found out that THY canceled the 9:40 AM flight from Antalya on April 19 and that this was possible 15 days in advance. I received an email and message informing me of the flight cancellation. As an alternative, I was offered a flight at 5:30 PM on the same day, which caused me to miss an entire day of my vacation and the planned events. I noticed that there were several other flights on the same day until 5:30 PM, but the business class tickets were available. If the company had acted in good faith, they could have offered a solution to fly me in business class considering my complaint. However, no such step was taken. Changing the ticket is not enough to compensate for the day I lost. What solution will be offered for this issue?