My radio in the 2010 Lincoln MKS-playswhen it wants to-all the channel

The radio in my Lincoln MKS-2010-plays when it wants to-first i was told it needs an amplifier-i bought one for this car-they put it in-the shame as before-i keep asking is there a loose wire? Because they screen shows what’s playing on them radio-what bcd is playing etc-but no audio-they act liken i’m Crazy-i’m At my wits end-can u help-the dealer says it could be 2 things-over $1,ooo/have they lost their minds-please help!! Mary-in Columbus,ohio!!