Got a problem with both mine and my wife's phone not connecting to the Warehouse network where I live (Patearoa, Central Otago).  This has happened intermittently before but has been fixed by usually manually selecting the Warehouse network again or by turning airplane mode on/off and the service usually returns, but not this time.  

I got on the phone to the Warehouse (2 degrees?) technical help desk for about 45 minutes and she got me to try swapping the sim cards to another phone, turning on airplane mode on and off and other things but this had no effect - still not working.  I was then told that they had no other reports of problems in my area and the problem was probably with the Sim cards on both phones (!?) and to get new sim cards.  How can this be that both sim cards would fail at the same time?  

Anyway, after this I took the phones to our closest town (Ranfurly) about 20km away and they both worked fine.  I'm going to ring the help desk again but I think I'm going to be told to get new sim cards again. Anyone got any ideas what's wrong?  If our phones are working elsewhere as above, this must be a fault on their cell phone network; wouldn't this be the case?