I'm really sorry to hear about this. I'd seen other posts on the displays cracking unexplainably.
I'm not a fan of dealerships. I'm not suggesting that they're being dishonest, but I wonder if they just plugged in a diagnostic tool as the first and final step. Based on what
@Tal said that could be your issue too, but it would not occur to them to check that.
I wouldn't call, I'd go by there and ask to see the bike with tools in hand, flip up the display and push the cable firmly in. Hopefully, the bike starts and you wave goodbye to them for the last time.
Whatever you decide, keep us posted.....