You might want to consider this.
My Uk phone credit ran out, but then the company disappeared also.
Currently I use a French (SFR) contract which suits me. I pay 7 euros a month line rental (inc taxes) and the calls are +50 cents a minute. Thing is, in an emergency you will need to make a lot of calls and will run out of credit on a pay as you go. Happened to me after an accident and the RAC could not find me to transport my car. Plus umpteem calls to get a loan car and various other things. I dont mind paying when I use it which is seldom. Usually only to ring wife each evening when out on one of my 'trips'. I only got one as wife insisted I have one when off alone tripping. My phone would not work at one campsite in the Spanish pyrenees. Apart from that it has been fine. You do have to ask them to enable it for international roaming. A nice touch is calls made in the UK to a UK number are local and quite cheap. The pay as you go are expensive because to run down the pre payment they are all routed through the originating country. So a UK payg phone used in France to a french number is expensive as it is routed to the UK for billing, then back to France as a call, making it TWO international calls. I switch my phone off. OFF not Standby unless I am making a call. That way the battery will stay charged for months.