Changing manually created permalink to old does not redirect

Hi,

My client wants to change the permalink from

/services-headspa/ (original url is /mainPages.php?9)

to

/head-spa-shibuya/ (same url)

I checked on the checkbox "Old" to redirect in case someone accesses to /services-headspa/, but it seems to redirect to a different page, which is /shibuya/ ( original url is /salonsDetail.php?salon=16)

These permalinks are all created manually.

How can I make my redirect change work for /services-headspa/  to /head-spa-shibuya/  which both are originally  /mainPages.php?9  ?

Thank you for your help.

Hiroko