Turkish Airlines Ticket Purchase Issue

Hello, On 02-11-2023, I purchased tickets for 4 passengers for the flights Istanbul Sabiha Gokcen to Dubai on 12-11-2023 and Dubai to Istanbul Sabiha Gokcen on 17-11-2023. The ticket numbers are as follows:
2352206977847: Serkan Nurettin C*****
2352206977848: Gokce Kosova C*****
2352206977849: Yagmur C*****
2352206977850: Uras C*****
I then paid ₺2,496 for seat selection.
On 03-11-2023, due to a change in our plans, I paid a penalty and fare difference to change our return flight to 18-11-2023 for 4 passengers from Dubai to Istanbul Sabiha Gokcen.
The flight was visible on the Miles and Smiles website, and I purchased 4 more seats due to the canceled seat payments.
However, on 04-11-2023, when I checked your website, I noticed that our flight was not visible. Upon contacting your call center, I was informed that the agent who made the date change made an error, causing the tickets to be voided. I then submitted feedback with the reference number TK-9739126.
Now, the flight tickets I paid for, the seats I purchased, the hotel payments I made, and even the visa obtained through your website are all in jeopardy, causing me to stress about whether I will be able to board the flight. During my call with the call center this morning, I was told that the response time is 7 days, which exceeds our flight departure date.
I am being inconvenienced due to a call center agent's mistake. I urgently request that my tickets be reinstated. I demand an immediate resolution to this issue, for which I bear no fault, and the rectification of our inconvenience.