Reopening Landline with original number from 5-7 years ago.

Hey,

We closed the landline account with my life long land line number 5-7 years ago.  I bought my parent's house and I would like to reopen the account.  I have his account info and can log into his ATT account.  There is no option for me to reopen the account that I am finding.  How do I get that number back?  It shows online that ATT Wisconsin still owns the number.  It does not look that it was given to anyone else from what I'm seeing through research.  Please help.  Would really like this for sentimental value.