I have contacted them formally through their agent in Johannesburg where I bought the gun. They have not had a reply back, but that is fair and reasonable given the time of year.I am at a loss as to why your rifle is opening on firing. This seems to be much more than a headspace issue. I agree with others, do not fire or alter it further until VC weighs in. Have you tagged them on this post? They are on the site but may not have happened on this post. Given your location difficulties, they may concede to work with a local smith to rectify the problem.
As to why it is opening, my take is that in a normal firing the explosion is directed forward and the reaction is backwards. In a split case near the base, with a little head space thrown in, the separated base in effect becomes a bullet and accelerates backwards violently. So you not only have the force due to the pressure of the escaping gasses right near the base, but an additional impulse like a hammer blow. Clearly the combined effect is massive as it has opened the breach every single time. Imagine the forces involved!
I agree with all of you, this is far too dangerous to fire the rifle again and as an engineer I am now absolutely convinced that any excess head space on a pivoting design with locking at 90 degrees to the firing plane is bound to fail.