This is how automatic billing is set to bill on Mortgage broker plan. Related article on Pricing with other useful information: HERE.
Mortgage broker plan has 2 types of users: Loan Processor type $59.99+GST (these users don't add their accreditations in and can work only under other broker's name) and Mortgage Broker that pay additional $70+GST to have Broker tools option available. Mortgage Brokers in that essence pay $129.99 + GST as stated on the plan, just that it's broken down in two charges - core one $59.99+GST which is counted in Loan Processor invoice and Mortgage Broker add-on of $70+GST in separate invoice.
For example, you have 2 billable users on Mortgage Broker plan:
Youself as Mortgage broker (charged LP $59.99 + MB $70 + GST)
Assistant as only Loan Processor (charged LP $59.99 + GST)
As Loan processor invoices are combined on org level - you got one invoice with two charges for LP subscription 2 x $59.99 + GST and other one with only MB $70 + GST.