Question : Wi-Fi greyed out iPhone 4S

I upgraded my operating system on my 4s to 6 & now I cannot access my wi-fi button as it is greyed out, it has

also affected my icloud backup, same thing its greyed out.

I went into my local Apple Store & they told me that they had never heard of this problem, they then told me

to connect to itunes & do a complete restore of my iphone, I have done this but its still the same, can anyone please assist?

Cheers