I hear about this ALL THE TIME. We had a guest last weekend who owns two airplanes. His second one -- a Piper Super Cub -- had been in the shop for ELEVEN MONTHS for an engine overhaul and recovering, with no end date in sight.
When I asked what was going on, he had no idea. He was really irked about it, and called the shop regularly, but just kept getting blown off, and there was really nothing that he could do, now that the covering was off the fuselage. (What's he gonna do -- fly it home?)
He is out almost an entire year of insurance, not to mention a whole year of flying. At his age, that is significant.