Issue with Turkish Airlines Ticket Change

I previously purchased multi-destination tickets for myself and my foreign spouse using my miles. To change one of these tickets, I contacted Turkish Airlines Customer Service. When I tried to make the change through the Turkish Airlines app, I encountered an error. I want to emphasize that I am calling from abroad. During my discussions with Turkish Airlines today, after explaining the situation in detail, my call with the Customer Representative was disconnected, and after a while, the call was terminated. No callback was made. My total conversation with four different Customer Service Representatives lasted 78 minutes (between 18:00-20:00). I was able to change my ticket for ₺111, but despite trying approximately 10-15 times, I could not change my spouse's ticket. On the last attempt, a ticket change fee of ₺2500 appeared. This price was higher than the original ticket price. Even though both of our tickets were on the same flight, Turkish Airlines could not explain this difference to me and could not fulfill my request. Since I cannot travel alone leaving my foreign spouse behind, I requested that the ₺111 change fee applied to my ticket be applied to my spouse's ticket as well. However, they said they would charge me a fee for this change as well. Turkish Airlines, which could not offer any solution, expects me to correct their mistakes with additional charges. As a Turkish citizen living abroad, I am deeply saddened that I can no longer recommend Turkish Airlines, our pride and joy, to my surroundings. If I may request your special support on the issue mentioned above, my request is as follows: to change my spouse's ticket for ₺111, and if this is not possible, to cancel the change made to my ticket free of charge and refund the ₺111 I paid for the change.