Of course, once a complaint was recieved there would be no doubt about handling it rapidly and diplomatically!
My concern was that; if you make a complaint link really obvious, does it make it seem like you get a lot of complaints? And thus put off new customers?
If you are talking about your existing customer complaints then it is better if some sort of ticket system be installed in place. You cannot expect your customers to tell you about their problems through a generic contact form.