Family Based Greencard

Hello,
I have a doubt with my F4 Visa. My mom's sister had filed an F4 for us and our case was approved and we are half way through the processing. But my name (since I crossed 21 years of age when the approval came) went missing in the approval letter but later we filed an application under CSPA for myself.

My real issue is with the Visa IV fee payment, as initially the fee was invoiced only for my mom, dad and younger brother and my name was not included. But later after we paid IV fee of 325$ for each of them, my name has now come up with a fee payment status as "Not Invoiced" while it is "Paid" for the rest. We further moved ahead with processing and filled the IV form online and had send the documents through courier for my family except mine.

Its been over 3 weeks and still my fee payment status is " Not invoiced".

I am in dilemma whether to wait until I get a notification regarding my case or to contact the NVC.

Any assistance in this matter is appreciated.

Also I would like to know, how long does it take for the NVC to schedule a visa interview after the hardcopy of documents are send.

We also had some mistakes in the IV form that was filled online and I would like to know whether its possible to make the corrections during the visa interview or should I write to the NVC regarding the same.

Thanks & Regards,
Nik