Both me and my mum have been with Virgin Mobile (pay monthly) for a number of years, we both have Samsung Galaxy S4 Mini's and we're both on our original numbers.
Over recent days, when I send a text to her, it sends okay (no failed message my side) however she's not receiving the text. She can text me and I receive them, however I can't text her. She is able to send/receive texts from other people who are on various networks as am I, it only seems to be my texts to her that aren't being delivered Unfortunately I haven't been able to find anyone else on Virgin Mobile to run a Virgin - Virgin check.
I'm loathed to make any dramatic config changes as the phones have been working fine and continue to do so bar the above issue. However I've tried changing network mode and checked the basics e.g. phone signal strength, network assigned etc. I've also tried re-seating the SIM.
The only change I made to the phone was to add an SD card however that was 3-4 months ago.
Frustratingly, this still doesn't seem to be resolved. After installing new SIMS on Saturday, we're still in a situation where I can't text my mum! My phone was functioning again a few mins after installing my new SIM, mum's took approx. 2 days due to her number (originally from a different provider) being migrated to a new system, something that wasn't communicated to her otherwise she may have elected to install her SIM after the weekend.
So after all that, the very thing we need resolved still isn't resolved, oh the joys!
I'm going to pop by hers tonight to try reboots, SIM reinserts etc to see if any of that helps, however I have my doubts.