Hello @ClareGrimsey ,
Welcome to the community,
Just take your SIM card out of the phone that is being repaired and put it in the other phone, simple. If that is not possible for any reason, just request a replacement SIM card or go to an EE high street store with photo ID and request one there.
To contact EE customer service dial 150 from your mobile phone or ring customer service for free using Skype or another phone: +44 800 079 8586 or +44 800 956 6000.
