I have had same query with them, I upgraded on 4th Feb, slightly different deal of 2 360 boxes, 2 360 remotes ,PSU's and cables. plus the Hub 4 Gig1 (£96.50) but had the additional box on the contract and now my 1st new bill, have spent ages on phone either send additional box or reduce my subs, with no luck 😞
you have 1 Additional TV Box, which should be a TV 360 mini box, if you have 2 360 boxes that is better than having 1 360 and 1 mini,
the oomph package is for 1 of each and that is why the bill is generated like that, it is a standard package that is on offer, lucky people seem to be getting 2 360 boxes I don't know why maybe there is a shortage of minis.
Hope this explains the billing, if you want a mini as well as your 2 360 boxes that will be an extra charge.