Red flashing light, new box sent, same issue

On Monday our Hub5 just suddenly stopped working, like literally completely out of the blue we lost wifi. 

Did the usual unplug for 30 seconds, plug back in and wait - didnt work, tried again and didnt work.

Unplugged from wall and waited, plug back in and didnt work. Tried again, still didnt work.

Made sure everything was plugged in properly and unplugged and plugged back in every cable and still just kept getting the red flashing light.

Spoke to someone on live chat, she said looks like issue with the box so they'll send a replacement. 

Replacement arrived 20 mins ago, plugged it in and straight away after boot up it's flashing a red light.

I work from home and need reliable WiFi, ive been using mobile data since Monday and it's not stable and I dont have unlimited Internet on my phone plan.

Why is a brand new box still flashing a red light?

How can this be fixed? Am I going to have to wait days for a technician to come and fix this?

I find it almost impossible and incredibly frustrating to get hold of virgin on the phone, I cant get to anyone on live chat until it's back on tomorrow