I am not sure what the correct reply would be for you, a letter back from them saying that they have recieved your cv wouldn't hurt, but some people will say that they recieve so many cv's they can't respond to everyone, but all I can say is just keep trying.
A lot of positions state their minimums & unfortunately a majority require persons already typed with some hours on type. Most positions require a minimum of 1,000 hours so at least you have that.
Once you get a foot in the door, this game becomes a whole lot easier.
Good luck!