You don't pay anything for a SIM card until you activate it and buy the first membership at which point you get charged for the membership and the once off activation fee.
So just don't activate the second SIM and you won't be charged anything for it.
If you need to contact 48 support about this then see the link in my signature below or email them at support@48months.zendesk.com
By the way, you probably shouldn't post your personal details on a public forum like this.
