If you swapped from a physical to an eSim, that will disable the physical one @Billy7
You either need to speak to customer services to see if they can re-activate the old sim, ask them to send out a new one (which will be active but can take a while to arrive in the post) or visit your local o2 store with photo ID to get a new one there and then.
All ways to contact customer services are in the guide Guide: How to find help & contact O2
It includes phone numbers you can call using Skype ( Guide: A Guide to Skype )
Please note, this is not customer services and we cannot access your account. Do not publish personal details (email, phone number, bank account).
Link to our guide on how to contact them can be found here
