Wi-fi repeatedly looking for networks, yet still saying connected - Macbook Pro (Retina 13-Inch Early 2015)

Despite W-Fi saying it is connected to networks - it still repeatedly says 'Looking for networks' (on and off) at which point internet connection seems to be lost for a few seconds (sometimes longer)

This happens intermittently, sometimes every five seconds sometimes every minute - Very frustrating.

It seems it is not the router as this is happening at multiple locations. (also tried changing the channel of router and other in the house don't have problems)

I have only had the laptop 2 weeks and have updated to el Capitan 10.11.1 since purchase - which may have coincided with the time this occurred; i can't fully be sure as at first I thought it was a lack of connection speeds. I do know it wasn't the case in the first week of purchase.

Apple support tried some possible fixes over the phone - including the moving and deleting of p.files (you'll have to bare with me I'm no tech whizz)

Likewise did some checks of the hardware which came up with no issues.

They suggested taking the laptop in store for it to be sent away for diagnostics; with the nearest time being in 6 days, and no knowledge of when it may return.

A solution i'm not fond of as am in the middle of writing a dissertation among other work.

Any ideas to fix this would be a great help!

George