iPhone 4s wifi grey out

My iPhone wont connect to Wi-Fi at all, its greyed out and won’t switch on at all. Before it greyed out this time it wouldn’t detect any Wi-Fi even though it was switched on. I have already tried putting it in the freezer it worked the first couple of times, now it doesn’t.

I need a quick solution to fix this, as I need it. Also I don’t wont do buy a new phone as well as I can't change it until the end of my contract which isn’t until the end of February. Does anyone know any more solutions please?!