Opt got denied

[Prathyushav]

Hi this is prathyu. My opt got denied because DSO of our school did not enter recommendation for opt into my sevis record before 30 days after filing my I-765 form.I submitted post completion OPT request to my DSO on June 10, 2015 but she could not process it because I had to submit full time enrollment waiver request as I had less than 6 credits in my last semester to complete my course(which I was informed later) and I submitted the waiver request form. DSO processed my full time enrollment waiver form and made a waiver I -20 after this process but she did not make my opt I-20 and did not update my sevis record. I mistook this waiver I-20 as opt I-20 and filed for I-765 on 6/23/2015.( I rechecked it with staff of office of international education while mailing to USCIS,but unfortunately they too did not inform that my OPT I-20 is missing!!!)I got a RFE request from USCIS on 9/21/2015 to submit my opt i20 which I did on 10/1/2015 with letter of explanation explaining what had happened and this is the date when my DSO updated my sevis record which is more than 30 days after filing my I-765 .On 10/26/2015 I got Denial notice from USCIS .USCIS read the letter of explantation ( mentioned in denial notice)but still denied stating the reason that there is no discretion regarding the requirement to file I-765 form within 30 days from my DSO post completion opt endorsement in sevis.I used my 60 days grace period after my graduation date( my graduation date is 08/17/2015 and my opt start date is 10/17/2015.)and my sevis status is completed now.

What should I do now??

What are the ways to solve this problem.

I am planning to file a motion to reopen or re-consider my case. ( which is asked to do within 33 days from notice)Which one will be better re-open or re-consider?? How many days can I legally stay in US??And are there any other solutions for this case please help me.

Thanks in advance.