I'm pleased to report I've fixed the issue regarding the WiFi dropping off and where no iCloud back ups were happening for my iPhone 5.
All I did was to reset the Network settings. This reboots the phone and then you just re enter the WiFi password details as normal.
My iCloud backups now work.
Settings > General > Reset > Reset Network Settings
I hope if you are having a similar issue this resolves it for you.
This may also explain why I was using a large amount of data from day one.
As the WiFi dropped off (when in standby mode) it resorted to LTE and downloaded all of my iPhone 4 settings from iCloud in this way resulting in a high data usage. I've since switched off LTE as I'm more than happy with the 3G speed and now the WiFi issue is fixed I'm happy. Battery life without LTE activated is also much better.
All I did was to reset the Network settings. This reboots the phone and then you just re enter the WiFi password details as normal.
My iCloud backups now work.
Settings > General > Reset > Reset Network Settings
I hope if you are having a similar issue this resolves it for you.
This may also explain why I was using a large amount of data from day one.
As the WiFi dropped off (when in standby mode) it resorted to LTE and downloaded all of my iPhone 4 settings from iCloud in this way resulting in a high data usage. I've since switched off LTE as I'm more than happy with the 3G speed and now the WiFi issue is fixed I'm happy. Battery life without LTE activated is also much better.