What happens if we cancel a 6-month rental after 2 months?

You will owe the remaining rental fees unless your contract has an early termination clause that says otherwise. Most six-month rentals are billed as a flat term, not month-to-month, so canceling early does not stop the billing. Read your contract's cancellation clause carefully: it might specify a penalty fee instead of the full balance, or it might require payment for the entire term. The rental company will charge a pickup fee for the service visit to retrieve the unit, which is standard because they send a truck and driver. They do not refund for unused service. Your standard portable toilet was placed correctly on level ground with good truck access, so that does not affect the cost. Call the rental company and ask them to explain the clause; they will tell you exactly what you owe.