That makes no sense. You can register for an Adwords account for free (just pay for your compaign). You can also register for Adsense for free, but there's no guarantee you'll be accepted.
Are you getting charged because you are going through an SEO or marketing company that has said something strange?
You don't need to pay anything to register for AdSense, you submit your application and get accepted or denied.
No need to pay any money to use and access Google Adsence or Adwards ... To display your adds in Google add network you need to invest money..
you don't need to pay anything for adsense setup. even for adwords, the amount you add to your account will be used for your campaigns. you can even find adwords promo codes online and you can reedem them to your account.
As others have said- These both services are free. Adwords is for business owner who want to advertise they business in Gogle and Websites using adsense ads and adsens is for the website owner who want to earn money by showing Google ads on their website.