Having trouble with sending texts.  All texts showing as sent but only approx 50% received by recipients.  Ported phone 18 months ago from 021 to 027 and have had no problems with a sanyo phone until now that I have  changed 10 days ago to an okta, and have since replaced that in the last few days with same model okta. the problem only began when I bought the okta.   No clues from telecom...any ideas?