Do you have dial tone on your phone? If not, can you please unplug your home hub and see if the dial tone comes back.
Which BT Home hub do you have?
Ignore the Retail Servers message, it just means the your home hub is not seen by the network because its faulty.
DACS does not support broadband, so its probably been bypassed.
I would suspect the HH4 has been damaged by the storm. If its out of warranty it may be quicker and cheaper to just buy your own router locally, or look for a secondhand HH4.
You could wait for broadband support to answer and deal, but that could take some time with the current fault level.
We are on a adsl connection, we only get 5mb max, live out in the sticks. Ok will have a look around for a 2nd hand hub
There are plenty of ADSL modem/routers available online, which perform better than the HH4.
TP-LINK TD-W8960N 300 Mbps Wireless N ADSL2+ Modem Router for BT Connections
Available on Amazon for £18.95. Other stockist may also have it.
Using the quick set-up everything else as default.
VPI [0-255]: 0
VCI [32-65535]: 38
WAN Link Type: PPPoA
Encapsulation Mode: LLC/SNAP-Bridging
PPP Username: email@example.com
PPP Password: bt
PPPoA service name: blank
MTU Size: leave unticked
DNS Settings: Ticked automatic
With no lights at all on the hub it is probably the plug top power supply, I had the same problem with a HH3, there's a label on the plug in power supply that tells you the voltage and current, which is 12V 1500 mA, you need to buy a 12V Switch Mode plug top power supply with 1.5 A or more output, available from a lot of Electronics component shops, cheaper than a new hub anyway.
If all you have is a copper line provided by Openreach, then all the Service Providers would be using that anyway. You are not going to get a better connection.
BT broadband is well supported via this forum, so its worth posting any issues here, as they usually get addressed.