Kinda figured that's where you might be headed.
Yeah, you hear it all the time. Foxpro this, Foxpro that, blah, blah, blah. BUT, that's because more people own and use Foxpros than all the others combined. You are naturally going to hear about them a LOT. They are good callers. FP has a well deserved/documented reputation for their customer service!
That being said, I can tell you this. Your lack of success is NOT because of the caller you are using. If your Western Rivers caller is producing any kind of a noise that half azz sounds like it SHOULD or WILL call a predator, then it SHOULD and WILL.
Look beyond the calling machine. Maybe look into buying the Tony Tebbe instructional DVD (or others). READ these forums right here on this board. Lots of free info here if you'll take the time to read it.
In my opinion there is nothing like being in the field and experiencing it hands on. If'n I was you, I would try very, very hard to find someone in your area that has experience, knowledge and success at this predator hunting game. Ask them, beg, bribe, offer to buy them lunch and gas. Whatever it would take for someone to take out and show you what it's all about. The hows, whys, whens. Heck, tell em you would just like to ride along, leave the firearm at home.
There may be someone right here on this board that may be willing to take you under wing and let you tag along. Put up a post asking/pleading for someone in your area to help a new guy out. Can't hurt nothing to ask.
Good luck.