Q: 14 month old phone, now loss of wifi after 1 minute

I have a phone on a 2 year contract with o2, i've had the phone for 14 months.

For the past 4 month I can use my phone but the wifi coverage gives up after using it for a minute, the spinning circle just keeps going round and not loading.

I can only watch 1 minutes of a video on my phone, alot of web pages dont load.

The only way to get the wifi working again is either disconnecting the wifi on the devise and starting again, or switching the phone off then on again.

I got new fibre optic broadband in the house last month incase it was our wifi, but thats not made any difference.

Other ipad/laptop/phone devices in the house with wifi have no problems, just my phone.

I have full insurance on my phone.

If i was to make the long journey to an apple shop and the genius section, would they repair it ? or if i send it off to apple ?

Thanks for any advice you can give.