Did you know fantastic help is an anagram of Planet Catfish? This forum is for those of you with pictures of your catfish who are looking for help identifying them. There are many here to help and a firm ID is the first step towards keeping your catfish in the best conditions.
I want to add a link to this thread and here's the last post, they are supposed to be C. liocephalus...
"...I am not sure what to look for id-wise, but I think they are a little more slender and their headshape is different from C. batrachus. But it may be almost ten years since I've kept C. batrachus this size so it's hard to tell."
I truly wonder why anyone would breed xanthoristic or mottled C. liocephalus, when there already are C. batrachus like that. So imo your fishes belong to the latter species.
Yea, that's what worries me too. I was really sceptical when I got them, but they are chez bred, so I should have known. I still think they might be liocephalus, as they had several batrachus'es listed too.
Reading this - Czech-made - makes me even more convinced that they are C. batrachus, despite the other listings. Sorry, I hope the LFS didn't rip you off.