My nicely walled, secure and normally sunny serene garden of Smooth Apple integration and functionality has been disturbed by Dark storm clouds from my replacement 4S, the seeds of trouble and disillusionment are slowly germinating as My 4s continues to not want to play nicely!
The reason for my Disillusionment I have attempted a restore. In fact several restores ! Machine resets, firmware restores, network setting resets in fact everything that seems to have worked for people in the forums BUT my Wi-Fi woes still exist !
One of the attempts was to go back to IOS6 which my replacement 4S came with, Yes, I kept the update file before I went to try IOS7 with my original phone, Unfortunately Apple, after a bit of digging around on the web have now revoked the keys to let me drop it back.
In fact one of my searches led me to search Apples own community forums. It seems that I am not alone with this problem, Admittedly I may be part of a small proportion of users effected but it doesn’t make me feel any better 
I feel a visit to my Local Apple Store is in order, hopefully they can sort me out either a replacement or drop me back to IOS6 where the peace and tranquility can once again be restored to my nice Walled Apple Garden.
EDIT
After an online chat and a subsequent telephone call my replacement is being replaced, will the replacement bring sunshine or darken the skies even further ? I’ll keep you posted !
Well IOS7 seems to be Apples buggiest release yet !
Oddities with lock screen ! Then Problems with WiFi even after 7.0.3 update. I’ve Just had my 4s in a funny WiFi on / off inverted state !
When The control center said WiFi was ON the system said it was OFF and entering to look at networks the toggle switch was ON but no networks were reported ( and yep there were several that I should have seen) .
Toggle the settings around and one was always NOTed!
A Device hard reset eventually sorted it !!!
Me thinks Apple rushed this OS release as it’s not to their usual standard !
OR my replacement 4S is faulty !!