Product: Student loan

I have asked by phone and in writing by certified mail for complete list of loans, copies of the promissory notes and complete accounting of the loan. I was told to file economic hardship with IDR and that each year would need to refile and they would send me notice of this to be done. I had in writing stating I do everything by XXXX, mail, NOT by email or website or by phone. I told them my identity had been stolen years ago and do not agree with the amount of loans. I also informed them that I had a XXXX and was making limited income and was self employed. In XXXX I received notice that I hadn't made payments when this was placed in the IDR and my payments were {$0.00}. I called and asked to have what I needed to file mailed to me. I received it and completed the required documents and mailed them back. I was told I would received notice if they did not received my paperwork by set date. I received nothing but letter stating again that I had payments of {$0.00}. 
The beginning of the month of XX/XX/XXXX I find out that I have missed payments. I had to borrow a friends laptop to go online to create a account with NAVIENT to find out what was going on and that they were sending notices to and old email I don't use and not by Mail as I requested. I called and was given rude comments about my loan and that payments required. I again explain I am self employed and do not make enough to make payments. My payments are over {$490.00}. I than send another certified letter with the completed paperwork requesting a XXXX XXXX XXXX XXXX. I could never get a clear answer what would be best for me to file. I also requested again the complete list of loans, copies of the promissory notes and complete accounting of the loan. I sent this by certified mail and also FAX it to them on XX/XX/XXXX. 
I also stated again that are not to call the phone number listed for it is my parents number and they are elderly. From XX/XX/XXXX to this date they have received over 5-8 calls a day and these calls begin from XXXX am/Arizona time till XXXX. They have answered and told NAVIENT to stop calling. I have told them to stop calling that I do not do anything over the phone do to fraud and I do not trust them to provide what they state is true. That I want all statements in writing. 
Yesterday, I received from NAVIENT two letters stating they can not process my requests for they need additional information. They need forms/documents of income proof ( basically my taxes ). I do not mind providing this information but I provided it at the beginning of the year XXXX, again in XX/XX/XXXX, which is were my information they either misplaced or as they claim I did not sent. I am sending them my XXXX taxes again, and certified by mail, again. Which is extra hardship for me. I do not trust NAVIENT, for I have ask for proof of loans and documents and they haven't send me but copies of unreadable documents and they have signatures that are not mine. There is so much more to this but I don't believe I have enough space to write it. Also, NAVIENT, has threaten me with Garnishment and that they will collect any of my Tax Returns. I have explained to them that I'm self-employed there is no employer and I used my Tax Returns for savings for those things that could happen. I will be honest, I'm XXXX old, self-employed due to my health and there will be no way I will ever be able to pay my loan of. I would love to be able to do a job that would pay me high wages and pay my loan off but I did not expect to have a XXXX at XXXX.