How do you thing you'll be able to get replacements if these that you have are standard minis?
Yes, you are right that it will be impossible to get replacement for the standart minis.
Biters seem to be this case.
Shooters however could possibly be miscast (they miss so much detail it does not look like design issue more like something that has to do with molding etc.).
The Time Bender even more so.
It is of course possible that Artipia produced all minis with this problems.
Then replacement is impossible, but we can still cry foul about the quality of minis.
I for example consider it a bad practice if you use other (cheaper, duller) designs than what you advertised.