What do you mean your product is "3C"?
Amazon won't show your listing in PPC ads if you don't have the Buy Box, so that's the first thing to check.
Amazon also won't show your listing if they don't think your product is relevant to the search term (even if it's PPC). This can happen if your listing doesn't include the keywords you're searching for or if the product is being listed in an inappropriate category.
Sometimes Amazon's system is just wonky and you've got to just create a new campaign.