Ok, First I'm not a dealer but I know dealers and worked with one. Yes, they'll backcharge you if the cust. which you sold the system to cancels before their agreement expires, you loose less the longer that customer stays signed up. They'll also backcharge you for a million reasons everytime somebody goes back to that job(as long as it is not equipment related) even when the customer is 90 years old, never seen a TV and doesn't speak English, is still your responsabilty to explain him how it works till he becomes an expert, if not , that's called cust. education and they will backcharge. There's also a million reasons that I can describe but don't have the time or space to say not do it, but that's just my opinion. Research better, you'll get better results