Taxi not tannery fault.
Hide prep makes all the difference. The tannery can't work wonders if they get a mess.
Hair slip tells me that something happened between Dec (when you dropped it off) and March (when they got to the tannery)
The whole order thing is non-sense. When you ship furs, you send a packing list of what you want done. (look at the moyles site) you print that off and add it to the packaging. The other thing that would and could happen is that you ship with you client information (meaning the taxi guy) and when it gets there, they would call and he would then tell them what he wants.
Sounds fishy all together to me and that he may have sat on the animals, then thawed them out, and then took a few days to get to them, skinned and fleshed, and packed up to ship. Then when the order got there, he didn't give them instructions and the tannery was sitting on it waiting. (given the comment about the order)
Now what you are left with is.. What about my hides??
you could call the Tannery back and ask if they are done? If so, you can explain what has happened and ask them to ship your furs back to you. Given that you had the tag numbers that should be very believable and you have the number for the game department for them to call and verify that it's infact your cats.
I would then either go in with the hides and again ask for a refund, and record the conversation, and if you don't. you can eat the cost of a painful learning lesson, or take the case to small claims, which is fairly easy. It takes some time, but this is easy.
You had a pic of the cats, i am sure, and you can when you call back the tanner ask about the condition again, and record that call, and write down the information. THen in small claims you can say this is what it looked like. this is the time line, here is the phone call with the tannery and the end product of what they sent back. You could contact a local buyer and have them give you a quote on the hides (as they would have been, if not ruined and then with the damage) get their card and add that to the total.
It's a pain, but doable and something you are going to have to decide to accept and do.
A tanned cat hide, even with slip around the head is still going to be worth something if you don't want to keep and hang them. (I wouldn't sell them to a buyer until it's all settled though) I get it, it would just make me mad every time i looked at them.