I closed and reopened mine. Message or email customer support and to save a bit of delay include your Date of Birth in the email as they’ll ask this from you.
I hadn’t used mine when I closed it so no comment about account activity.
Don’t forget that your GIA and ISA will have different payment references if you’re manually setting a payee from your bank.
Send payment to the wrong one and you’ll need Freetrade support to move it over for you.