That’s not making sense , are you saying you were already on BTDV (so your phone was connected to the old router and working , but the new router , which you don’t really need , doesn’t supply telephony like the old one did ) or your telephone is still connected to the wall socket as it’s always been , but it has stopped working even though the changeover date is the 20th July hasn’t been reached ?
The big phone is probably the backup phone that works in a power cut - should be a white Motorola FW500 hybrid phone.
You should be able to get an free adapter adapter so that your phone can stay where it is if there is a spare power socket available.
Am very surprised that you aren't expecting someone to set things up as it was standard if you were getting the Motorola phone as that isn't given to everybody. You should have also had the option to order an adapter from the get go.
Thanks for explaining all these details for us, @Noura.
Based on what you've mentioned here, I definitely think it's best to see if we can get a bit of clarity on the details of your order, and what exactly is switching and when.
As is indicated on our help page here, you can give our team a call on 0330 1234 150 for any queries around your switch and setup and they'll be able to say for sure what's going on here.
Peter