Further, in ClickBank's Client Contract with Vendors it states:

ClickBank Client Contract

....

6. If you promote products listed by ClickBank, then:

*You agree to make no such promotions that suggest or imply any warranty or other policy that might conflict with ClickBank's eight week return policy.

....

Survey Sentinal Notes:

From the above statement of policy, it is clear that Vendors definitely do not want to have sales revoked(!) because of the penalties and charges involved.  If a customer requests a refund, it is generally given without dispute, to avoid having the customer revoke the charge against his credit card at his bank.

For your security, when you sign up for any paid survey service, make a copy of the website at the time. Microsoft Word 2003 can be used to do an excellent job of this.  In case of future disputes, this copy will let you demonstrate what was promised and compare it with what you received.  This could be especially important to show your bank, to demonstrate that you did not receive what was promised, the vendor made material misrepresentations, or whatever. 

Make a copy and keep it for yourself.  Most probably you will never need it.  But it is better to have it and not need it than to need it and not have it!  ;-)

- Jorge Chavez