I had the exact same thing happen, just with a 2014 Hyundai. Only aftermarket remote starts were available when I bought the car, so that's what was installed at the dealer. Took it in for a recall repair 3 years later and the remote start was broken when I picked the car up.
Contacted multiple dealerships and they wouldn't touch it since it's aftermarket (despite being installed at a dealer). The shop that did the recall repair flat out said I couldn't prove it was their work that broke it so they're not responsible. My only option was to take it to a local shop that does that type of work. Audio install and aftermarket mod shops were the best bet.
Hey, TigerClaw. Looks like the Lemmy error of throwing your comment into another thread happened.