Surname Changing NIGHTMARE

I have been trying to change my surname from Morrison to Morrison-Mac Innes for a whole week now, been on call for 45 minutes, on their private chat twice and into a branch 3 times and they cannot add a hyphen to my surname because their system wont allow a hyphen! To make things worse, I need it to reflect CORRECTLY on my banking details in order to claim my Maternity UIF.