Default [Q] call volume

Hello,

My P780 has ceased to have audible call volume after less than one months use.

It had been absolutely fine and then overnight just ceased being usable for making calls. I don't mean it's not as loud as I'd like it to be compared to other phones -- I mean it is unusable, there's nothing but a tiny little mouse voice on the other end with barely a sound being audible.

Just in the process of doing a factory reset and wiping data off before the ineveitable warranty claim due to faulty hardware.

On the off chance, has this happened to anybody else's P780 and were you able to fix / correct this by refreshing OS or by any other software means ?

thanks in advance