Yes, we are also having problems, we also wanted to watch this series and episode 2 is missing.
Starzplay via Virgin Media seems to be a no no with all the issues others and myself have had, and to say "Starzplay have decided not to make the rest of the series available" is an awful response and not true, the whole of the series is available on the Starzplay app!,.... but it's not available if you buy the app via Virgin Media.
Why offer boxsets if they are only partial?! I hope you had luck getting to the bottom of this as no one seems to be answering you in here.
I think I'll cancel mine through Virgin and sign up to Starzplay directly.