Why cannot I receive text messages from one mobile number any more?

For some reason I cannot receive text messages from one contact number any more. I have received text from other people and their messages come in no problems. I can text the number without any issue, however every time she sends text to me it says it was sent... I have gone into all of the block/spam settings and there are no blocks set up on my phone or hers. She has had her service provider check her mobile with no problems saying problem is my end. I have put my SIM into other mobiles same thing happens. When I text to this number using another persons phone her messages come through ok. My service provider BonBon gave me a new SIM card but nothing has changed. Any ideas!! Thanks Pam

Try this. Delete her as a contact. Clear your cache and reboot. Confirm no block on her or her number. Readd her as a contact. Retry to send sms. Good luck.

Welcome to Android Central! Did either of you ever use an iPhone? If so, check with Apple Support to make sure your numbers have been completely removed from the iMessage servers.