I was not able to PM you, I get an error--- 'User 'BitcoinPSU' is a newbie, but your options are set such that you cannot receive PMs from newbies. Therefore, you cannot send PMs to newbies, either.''
If you have Skype you can add me: tomcom229


I believe there is no expiry for them,
However you have to use them from time to time ( at least minimum every 6months) or they will get deactivated ( that's just what's written in the Terms for that Mobile operator)
Have had mine for about 3years and I use it as my main SIM, however it's not possible to top them up unless you are from UK, so you can use them just for the free 200mb Data or to Receive calls/texts.