Errors on H1 approval notice

[h1error]

I've applied for H1 through premium processing and got the approval almost a month and half ago.
But the year in my date of birth was printed wrong in the approval notice.
I've got appointment for visa stamping on Dec 29 '04.

Pls advice me on
1. if I really need to send my approval notice back for correction before the (interview for stamping)?

2. Do I need to pay fee again for corrections?

3. How many days it's going to take for me to get it corrected from INS?

I appreciate your responses