Why do you want to delete your account and start afresh instead of using another SIM as a replacement with your existing account?
Seems odd.
Especially since it means that you'll lose your original phone number, membership plan, cash credit on your account etc.
If you really want to do that then you'll either have to activate the SIM using a different email address/login/account or contact 48 support and ask them to delete your existing account so that you can re-register using your original email address.
If you actually wanted to get another SIM and activate and use it with your existing account then you should have ordered a replacement SIM rather than a brand new SIM.
However if you contact 48 support they may be able to assist you with activating the new SIM as a replacement so that you can continue to use it with your existing email address/login/phone number/membership etc.
This is the normal way to leave 48 and have your account eventually deleted:
To contact 48 support see the links in my signature below.
