Bluetooth phone volume


I’m having difficulties hearing the other person while on a phone call. I’ve gone to my audiologist and he can’t figure out why all of a sudden the volume level is extremely low. Called my phone provider and Motorola and they don’t know, they day I need a new phone of course. So I’m needing help on how to turn up the volume. By the way, if I use the phonak controls, it makes my end extremely loud and still can’t hear the other party.