Fair comment, but they are no different to any other mobile carrier in this respect. The most common "vector" for phone misuse is so-called water damage. Every six weeks or so while I was in contract, I took a photo of the water damage indicators on my Samsung. It doesn't prove anything outright, but it does demonstrate on balance of probabilities that it's been reasonably well looked after.
A broken (cracked) screen is not a warranty repair. Anyone who has this sort of broken screen knows that it's not going to get fixed for free, and should just make their own arrangements which are always going to be cheaper than anything Virgin offer - even if it's fixed at the manufacturer's premises.
This will be a chargeable repair as a broken screen will void the phones warranty.
You can arrange for this to be repaired by calling us on 789 or 0345 6000 789 or you can book the phone in for repair in your online account here and going to Plan and Device > Phone repairs > Phone fix.
We'll send you a repair bag to send back. We'll take it all on board from there.