Audio muted :(?

Hi everyone I have a ford focus zetec 2012 model. Everything was working fine up until 2 days ago I went to make a call through Bluetooth and it just displays audio muted and doesn't do anything I've held the on/off button for 15 seconds it went blank but didn't fix it as it's still displayed. Am on the road everyday for work and would love of someone knew how to resolve this issue? Thanks so much.