Can I submit federal and state tax returns without an SSN/ITIN?

[jd10132112]

I moved to the US a few months back, and despite being eligible for an SSN I have been unable to obtain an appointment to get one (hundreds of phone calls have gone unanswered, and I was turned away from the office when I tried to go in-person). I very much doubt I will be able to get an SSN by 18th April. Also, since I am eligible for an SSN, I am ineligible for an ITIN. 

I have prepared my forms using Sprintax (recommended by Turbotax for non-residents), where I used a temporary SSN given to me by my employer. Is it acceptable to mail in my federal and state (Maryland) tax returns with this temporary SSN crossed out, with a note explaining my situation? Otherwise I do not see how I can submit by the 18th April deadline. Even the forms for requesting a deadline extension seem to require an SSN...

Thank you in advance. 

[FangxiaL]

You need to apply for an SSN first before you are able to file your tax return. Try to visit a local Social Security Administration office. 

www.ssa.gov/forms/ss-5.pdf

[jd10132112]

I visited my local office with my forms signed and my passport, they said I had to leave because I didn't have an appointment. But I can't make an appointment because no one picks up the phone.