After you explain it to the representative by phone, you had better request appointment with the local filed office to talk to them face to face. If you can make an appointment, you had better bring the copy of the letter you sent to NVC through the inquiry form. Hope USCIS can correct the mistake and reopen the the case on their own after you explain it to them.
If they cannot reopen on their own, you may file I-290B Motion to reopen within 30 days from the date the withdrawal notice was issued (the sooner the better). Provide a letter explaining that you did not request withdrwal of the I-130 petition with the I-290B filing. You need to go to the Notary Public (e.g., your bank) to notarize your signature on the letter. Also provide the copy of the letter (in the inquiry form) you sent to NVC with the I-290B.
