Rowan Amore

Legacy last names are no longer available.  This was all covered when LL started the new last name program.  If you really want the same last name as your partner, they would need to change as well.  Also take into consideration that name combos may not always be available if you plan to keep the same first name.
https://community.secondlife.com/blogs/entry/4114-now-available-last-names-in-second-life/

Check to.see it the store has a redelivery terminal.  Hit that and it should have your item listed on the website.  We've all done this at some point.