Where do I file a complaint for one of the support "experts"?

Im currently having similar issue's iv managed to get through to 2 different people both have cut me off then itd only let me set up a call wich iv done but then i get a email saying they couldnt get through even tho iv been sat by the phone waiting for them to call im livid im being messed around like this and now just want to put a complaint in any ideas how to speak to a real person