Turkish Airlines One-Way Ticket Pricing Issue And Return Add-On Complaint

I purchased a one-way ticket from Turkish Airlines for the Ankara–Detroit flight. Once my return date was confirmed, I wanted to add a return segment to my existing ticket, but Turkish Airlines said this was not possible. The real issue is this: • One-way return ticket: $1,264 (≈ ₺53,500) • Round-trip ticket for the same dates: ₺42,000. In other words, due to Turkish Airlines’ pricing, a one-way return ticket is more expensive than buying an entire round-trip ticket. When purchasing my ticket, there was no information stating that “a one-way ticket cannot later be combined with a return flight” or that “one-way return tickets are significantly more expensive.” Because of this lack of information, I was deprived of the chance to buy a more reasonably priced round-trip ticket. Despite writing to Turkish Airlines multiple times, none of my detailed explanations were answered; I only received generic copy-and-paste responses with no solution offered. I have suffered a financial loss due to Turkish Airlines’ insufficient communication and lack of proper information. I am requesting a fair resolution to correct this issue.