Ye_Olde_Crowe wrote: »I'm not home so I can't check myself, but I will do later - thanks for the warning.
Anyway, are you sure you checked on the character you bought the slot with? Ourfit slots are per character, not per account.
EDIT
If the issue is not character-slot-related, then it might be connected to this forums banner:
"The issues affecting purchases in the ESO store have been resolved. Thank you for your patience!"
In that case you might want to open a ticket with the ESO support.