Hi

I need a suggestion for a SIM plan

I need a UK SIM-only plan with something like the pay-as-you-go
scheme. I'm based abroad, I'd like a SIM with not expiry, to be
"recharged" by credit card and no contracts. I've experience with
German/Italy/France mobile operators but not with ones in UK. I'll be
in London at the end of July and I'll buy my SIM
No virtual operators (like united-mobile and similia)
Do you have any suggestion ? operators' web sites are a bunch of not
uncomprehensive marketing slogans :-(

Thanks, Alex