If a company's product or service is bad, there's no amount of free stuff that they could offer that would improve my image of them.
What does improve my image of them is if they acknowledge the problem, treat it (and me) seriously, and make a credible-sounding promise that they'll fix the problem in the future. If all that's done, giving me a refund or replacement will further enhance the company in my eyes, but if it feels like they're just buying me off, it doesn't.
I realize that. I'm saying they're not actually solving the problem, nor are they improving their image. In some cases, sure the customer has been wronged and a replacement should be sent. But that's only half the solution, and the less important half at that. More importantly, they have to find a way to prevent that problem from happening again so they don't alienate the much larger group of people who will never complain but will simply switch brands.
You'd be surprised how often that is true.
Most companies are willing to send free stuff in order to improve your mental image of their product or service.