Hi all posting on behalf of the wife.
She moved to an S20 from iphones and stayed with EE, She asked for her old number to be transferred to the new sim, which EE have done. However when anyone sends her a text to mob number ending in 208 she receives it on the correct number but when she replies it shows and replying from a different number ending in 247. Now i know she didn't read the manual. How can she change this? Cheers
So to confirm now, if you were to check with EE the wife Is only paying for just one mobile number?
If this is the case, then the quickest easiest fix may be go to messages app, press three dots in right. Press settings, go to chat settings, turn rich communication/chat off