Used Temper and didn't receive an invoice? That shouldn't happen.
This is often related to the set up of relevant e-mail addresses and permissions in the User Admin section.
Set up users correctly:
Select the appropriate company and scroll down to User Admin.
Add invoicing visibility permissions for existing users, by checking the Finance box for the related person.
Want to add a new user? Click the gray Add Colleague button, fill out the correct details and make this person responsible for accounts payable, by checking the Finance box.