SARS callcentre agent refused to help me and put me on mute for almost 10 mins

I requested a callback and the agent that called me back pretended not to hear me on the line, at first there was a connection issue and I moved around to make sure the line was secure. She just kept quiet and kept putting me on and off mute. I need that call listened to because she flat out refused to help me even after I gave a chance to do so