Recovering audio from a video

So today my girlfriend played the flute, I videod it and attempted to send it to her via an app called telegram, this did not send however as I had no wifi. My phone unexpected wiped my videos off my phone so I went to telegram to get the video off there and all the audio was gone. I really want the audio back as she is moving away and I was going to send it to her as no one else filmed it. Please help me.