Replacement sim not activated

[Blockhead9]

My phone was lost so ordered a replacement SIM card (same number)to put in another phone. It came but not activated. Can activate it via the app but it wants to send a security code to my number. (Old sim lost and new sim not activated) so can’t get security code. Online help is hopeless. Going round in circles. I’m almost deaf and can’t hear the staff on support line. I’m 86 and housebound so can’t go to a store. What can I do to get my replacement sim to work? 

[MI5]

@Blockhead9 

This is a customer to customer community, not O2, so we cannot access your account, sorry.
You need to contact O2 to lift the bar from your account.
Message them on Social Media. Facebook (https://o2uk.co/O2CFB) , Twitter (https://o2uk.co/O2CTW) or Instagram (https://o2uk.co/O2CIG) or give them a call on 202 or 0344 809 0202 (contract) 4445 or 0344 8090222 (PAYG) Guide: How to find help & contact O2