We have a scenario where a joint owner requested a new card and pin number for the other joint owner on an account. Our line of business refused to do this and we have a client complaint as a result. I do not think we can refuse the request for the client but do others see it differently?

Joint account? Ask your "line of business" what risks are they trying to avoid??? Also pull out your depositor's agreement, it most likely states that you can act on the instructions of any joint accountholder regarding the account.