EAD (WorkPermit)

I applied for 17 month STEM OPT Extension. I came to the US on an F1 visa.
6/14/15 - USCIS received my application
Sometime in July - No update in my case thus far. Apparently I was sent a biometrics appointment letter, but I never received it (I discovered this in August because I had no idea I had to go for a biometrics appointment in the first place, evidently online filers are required to, while paper-based application aren't. Go figure)
07/29/15 - Initial OPT EAD expires
08/19/15 - I receive an RFE - There was a discrepancy in the employer name in my application: my I-20 and supporting documents listed the company I worked at, while the application listed the staffing agency I was employed by. I was asked to send in documents clarifying who I was working for. In addition I was asked to attend a biometrics appointment and include a stamped copy of the appointment notice to the response to the RFE.
08/22/15 - Called USCIS. Explained to L2 officer that I never received the first biometrics appointment, and asked to be scheduled for a new one. The officer proceeded with my request and asked to wait for about 2 weeks for the receipt of my new biometrics appointment.
09/08/15 - Called USCIS again. I never received the new biometrics appointment I had been promised. It turns out the L2 officer I spoke with failed to schedule a new appointment despite assuring me he would. I asked to be scheduled for a new appointment again. At this point I'm very stressed out, I've been out of work for a month or so now, and my old job has agreed to keep my position open for me, but their interest has began to wane. The L2 officer promises to schedule new appointment and asks me to wait a further 2 weeks.
09/22/15 - I am mailed my new biometrics appointment, due to be attended on 10/09/15.
10/09/15 - I attend biometrics appointment. I make copy of stamped appointment after my attendance, add the required documents clarifying the company name, and mail them with the RFE notice back to Vermont Service Center via USPS
10/14/15 - USPS sends delivery notice of documents to VSC.
10/15/15 - No update on USCIS website as to whether the response to the RFE has been received. I call three times and finally get hold of an L2 officer, who tells me my biometrics have been received but there's no news on the response to the RFE I mailed. Agrees to open a request for my case since my case is outside the processing time limit.

At this point I'm highly stressed out. I can barely eat or sleep because I'm so worried and I've been out of work for a few months since my EAD has expired. Is there any timeline as to how long it takes to be approved once the RFE response is received? Do I need to contact my congressman to open an expedite request for my case, and if so how.

Thanks in advance for any helpful information - I really appreciate it.