Help I've lost the front and rear adjustment...?

Hi there,

I've just had an amp installed in my skoda rapid.

We thought it would be nice and straight forward... Speaker outputs to hi-level inputs on amp... All connected up as it should be and away you go?

Not exactly what has happened... Turned it on and the swing unit has lost its ability to fade from front to rear - the setting that was there has disappeared!?!?!

The signal for the front speakers has disappeared so only the sub is working.

Anyone got any ideas? Please help...

Jon