@Peter44Hi it is hard to get to O2 via the internet. You need to call customer service on the numbers in the link below.
https://community.o2.co.uk/t5/Other-Products-and-Services/Coronavirus-Covid-19-Community-Help-and-Su...The best one to try first is the one ending with 4005.
But since things are going slow it will likely be that the time you might receive your repaired phone will take long and if your phone is needed urgently I will ask you to find some local expert who can fix the screen for you.
But you still can call them to see how they can help.
Hope this helps