I have had the same thing happen to me in the past, they will give you the miles, but they are going to ask you several questions. If you have the information for them when you initially send the email, then you will get the miles a lot faster.
They will want to know the following....
1. You Advantage Number
2. The day you did the survey
3. What the survey was about (Example:Beer or magazine covers)
4. How many miles were offered to you.

Email the above information to [email protected].

You shouldnt have any problems getting them to credit you with the miles.
Good Luck