Help Can't connect to home wifi

[Ungifted]

I was recently away for a few days and exceeded my data allowance. My phone went down to about a 4% charge but seemed to recover after charging.

My problem now is that I can't get it to connect to my home Wi fi. I go to settings, press Wi fi on and get a message Turning Wi-Fi on but nothing happens, it just turns off without connecting.

I had no problems before I went away and both my PC and tablet are connecting okay.

Any suggestions please?