Downgrade the AK and M4 mark X

I upgraded the AK mark 1 because I was forced to when I logged in for the first time in a few months and I don't want it. I want the original AK Mark 1 but we are not given an option to downgrade, and I've contacted Z8 support like 5 times and they've said they can't delete or downgrade it for me, which is really annoying. Any possible way to do this?