As the earlier thread says, there is an automated sorting system. The reply may be no more than an acknowledgement they received it. Same as if you sent it recorded delivery!
I worked for Flybe for several years on both turboprop and jet fleets and I would definitely say they can be a little strange in their recruitment. You could recommend someone, and they could even be "offered" a position but then still not get anywhere, and others just come straight in.
Never did work it out. They are a great company to start with and the DHC8 is a fine aeroplane to cut your teeth in commercial flying. I would suggest persistence is the name of the game. Try writing directly to the tuboprop fleet manager and sell yourself to him. Send the same letter to personnel and even to the ops admin manager. Get your name known. Do be aware you may well not get a reply at all as there are large numbers of people anxious for that first break and it is quite likely many will have more to offer.