Another outfit wanting money up front before starting work

I contacted this company to visit my home and quote to supply and install a beam across my car port and link it to our existing alarm system. Having received their subsequent quote and accepted it I then receive an invoice for the full amount quoted and an email requesting FULL PAYMENT UP FRONT BEFORE THEY EVEN START WORK! Sorry, I'm not into bank rolling other people's businesses even for a mite over R3600. What a cheek! This sort of nonsense is rampant in South Africa and needs to be stopped dead in its tracks. And the "excuse" for this behaviour from businesses like this that so many clients fail to pay up on time after a job is completed is unacceptable. Running any business involves judging, evaluating and accepting a degree of business risk. If a company tries this caper on one's immediate reaction surely should be should I take a risk on THEM, what if their workmanship is unacceptable, what if they don't deliver on time and finish the job properly? If these businesses are so hard up for working capital is it OK to ask the client to finance their operations? No ways. I have called in another professional who I know who will do a good job and only expects full payment on completion. THAT'S the way it should be done, Astron. Don't expect my custom ever again.