Take it back!
They've disconnected something or blew a fuse, I'd guess.
Resetting the maintenance minder is simple on the HCH-2. I imagine it's similarly easy for your HCH-1.

Steve

STOP terrorism - Drive a HYBRID

Vehicles:
350 miles a week ------------ 2006 HCH II, Magnetic Pearl, w/NAVI (born on May 25, 2006)
350 miles a month ---------- 2003 Mazda Tribute ES-V6
350 miles a year (for now) - 1986 Mercedes 560SL