SunExpress Flight Delay and Customer Service Issues

SunExpress rescheduled my August 18th flight XQ841 from London to Izmir to August 19th, asking me to contact customer service for approval or rejection as mentioned in your email. When I called your call center to discuss my inconvenience regarding the one-day delayed flight, I couldn't get through at all. While hourly delays can be somewhat understandable, postponing the flight by a whole day when my travel is imminent was an unpleasant surprise. Your call center says to call back if the flight is not within 24 hours. So, how does your call center plan to resolve my accommodation issue related to the rescheduled return flight within 24 hours (assuming we can even get through, which is doubtful)?