Keep working with your dealer and or your electrician to get this resolved.
None of this should cost you any money.
The spa is under warranty, and the electrician should correct anything that may be wrong with the wiring.
Be sure you have a 60 amp breaker installed if you jumper is set for 60. Or if you keep the 50 amp breaker, have the dealer set the spa back to operate on 50 amps.
Hopefully it won't come to this, but if you get to a point where the electrician points to the spa dealer, and vice versa, have them both out to you spa at the same time, and let them work the problem together.
Brewman