There are hundreds of airlines all over the world where the call sign doesn't match the airline name - Nor does it have to.
Prime example - British Airways' callsign is Speedbird.
Over here there are many more -
Jet2 = Channex,
MyTravel Airways = Kestrel,
FlyBe = Jersey,
BA Regional flights operate under Shuttle or Flyer
Thomas Cook were formerly TopJet
TNT Cargo Flights use Quality
Europe Airpost uses Frenchpost
Maersk Star Air cargo (For UPS) uses Whitestar
Over your side of the world,
PanAM used to be Clipper,
Pinnacle who fly for Delta Connection apparently use Flagship,
Republic use Brickyard
Kalitta Cargo use Connie
......And the list goes on.
Check out the Wiki link. Very good resource should you hear something you're not familiar with!