Don't quite understand the time at the dealer.... but you will need to be able to use a voltmeter and start chasing where the electricity is supplied from and where it stops. Sounds like a breaker tripped you haven't found, or another GFCI you haven't found that is upstream of the outlets that don't work. Sometimes, the breakers themselves can go bad. Other things to consider is checking all ground/negative wires in CB panel box for tightness. Be careful, also, doing all this--or get an electrician to trace everything.
Doubt Jayco can tell you where the wires are, or would.
'16 40QBH Phaeton
'15 38RSSA Mobile Suites--traded
'05 36TK3 Mobile Suites--retired but not forgotten