[Swan]

I have an old iphone 5s (i know, ancient, but it's been doing what i need for years now), anyway it wont receive calls or texts. I can make calls, can use the internet, whatsapp etc, single is reading fine, no problems with o2 in my area, do not disturb is off, turned the phone on and off several times, but still not working. I know it's probably time to get a new phone, but this problem is baffling me now!

Any help would be greatly appreciated.