I've had the same problem and it's incredibly frustrating. I had a new SIM sent out and that seemed to work for a short time but the problems have recurred. For me it seems to be exacerbated by trying to receive calls from my bank. I've recently set up accounts that require automated calls to authenticate payments, and even if I know the service is working (I test it now by sending a text to myself, and checking I receive it instantly) when I wait for this automated call to come through it kills the connection, and then I lose the ability to receive texts. This lasts anywhere up to a number of hours/half a day. I've tried everything - restarting the phone, removing and reinserting the SIM card, leaving the phone off for 15 minutes, and factory resetting the phone, and the problem persists.
Similar to you, I can still make calls, send texts and use data during this problem, which makes no sense to me! It's like my phone has been blocked from receiving just texts and calls - why can I still download data over the network? I wouldn't mind so much if it was someone I know trying to contact me, because they could send me an email/Whatsapp message to let me know they can't get through, but this is important - trying to make bank payments. Especially because it seems to happen again when the service is back up and running, the automated call kills it. Even more frustratingly, sometimes it gets through, so I know it's not down to the number the bank is calling from (which is an 0845 number).
I've spoken to someone about this at Plusnet, and they've done some test calls and logged it with a team who are supposed to be looking into it further, but I just can't explain it.
Please let me know if you find a solution. I'm sure your new SIM will work for a while but I'd be interested to know if it starts happening again.
