Turkish Airlines Unauthorized Ticket Change for Istanbul-Osaka Flight

My cousin M***o* had a flight from Istanbul to Osaka on 28/01/2024 and a return flight from Osaka to Istanbul on 25/02/2024. We were supposed to return together from Osaka to Istanbul on 25/02/2024. (My departure date is 16/02/2024, ticket number TQM3NQ.) On 02/01/2024, I received an email stating that there was a time change for the Istanbul-Osaka flight and that we could either accept the change or make a new arrangement. After this, I couldn't access my Miles and Smiles account with my password. After resetting my password, I received an SMS from TK info about a travel change. I intended to accept both flights as they were because the time change did not affect our travel plans. However, due to this unauthorized action, both of us are now facing issues. All our holiday plans, annual leaves, and reservations were set for the departure on January 28 and return on February 25. If this action is not reversed, we will face significant problems. Customer Service informed me that they couldn't assist in reversing the action. I tried to log into my Miles and Smiles account to confirm both emails, but the system did not accept my correct password, so I had to reset it. A few minutes after logging in with the new password, I received the travel change SMS mentioned at the beginning. I request the cancellation of this unauthorized action and the restoration of the flights to their original dates. Clicking the link in the email to change the flight now requires an extra 30,000 miles. If this erroneous action is not reversed, my cousin and I will be severely affected. My intention was to confirm the time change for the 28/01/2024 flight through the link in the email. However, as previously mentioned, I couldn't access my Miles and Smiles account with the correct password and had to reset it. A few minutes after logging in with the new password, I received an SMS about the travel date change.