Thank you JoeF, but the point is that I mail out the renewal the same day of the approval.
When they process the renewal package, they should be able to find my I-485 has already approved and there is no point to process the renewal, and should return the package.
I noticed the I-765 and I-131 forms have the "fee is not refundable". But I still feel this is not quite right.
Thank you for your advise.