Idea taken by manufacturer?

One of my manufacturers I use make certain collectible items and I sell them. They also allow me and other competitors to come up with our own ideas for the collectibles and allow us to sell them exclusively at our stores so no one else can sell them but me. 2 years ago I created a concept which they drew up for me but I held off on doing it. Now 2 years later I see a competitor of mine selling this collectible I created. Note their version is slightly different than what I created but you can tell by their design they are selling it is my concept due to all the detail I originally put in. basically it is to coincidental to say they came up with all this detail the same way I did.

I contacted my manufacturer and asked why they gave my idea to another competitor and they denied they did but I have my concept artwork here and what they actually made and you see how similar they are. Is there any legal lawsuit there because this manufacturer yanks my chain a lot. I don't want to get into to all the other things they do but they are like used car salesman. I dont have my concept artwork copyrighted or anything but just checking my options as I am ticked!