Poor service from agents

Called in the call center to update my booking details as i had initially made a booking and requested 1st sitting as i am traveling with a 6 year old and a mentally challenged adult. After i called to change cabin details, my dinner was changed to 2nd seating. I called in and requested 1st and was refused so i explained my reasons and requested to speak to a manager and was told to hold on. 21 minutes later the call just cuts and no call back. This is so annoying as agents should be trained to be professional and come back on the line timeously and let customer know that they have not been forgotten.