Need Help With Total Credit Recovery/Ontario Gov

I'm writing here since I need some advice on how to proceed with my Ontario student loan.

I have an outstanding loan that went to Total Credit Recovery (TCR) which I have been paying down.  Being aware of how others have had issues with this firm, I recorded the entire call when I contacted their office yesterday to set up a final payment for the loan.  At first, I was offered a settlement amount from the first agent I dealt with.  He confirmed that a letter with this settlement would be sent out without any technicalities (eg "this is a first payment...") and offered a due date in late August.  He also confirmed that the amount "would be no greater " than eight dollars over the amount he initially offered.

After details were confirmed though, he switched me to a second rep who tried to up the amount a bit and then abruptly transferred me again after I asked inquired where the extra amount was coming from.  When I got to the third agent, things got really ugly.  She claimed to be a supervisor during the call and said that due date had to be Aug 9 (I insisted that I was already offered an additional two weeks and that with the Civic Holiday, this was only five business days away if the letter went out on Aug 1).  She also tried to increase amount again by $45, before going back to an earlier amount, and continually threatened to revoke the settlement offer (I always responded to this with a "are you threatening me?", which caused her to change topics). She also claimed that interest would be accruing during the time it would take to mail out letter and insisted on faxing details to get the payment yesterday as the only way to make sure I was finally settling the account (I know enough to know that this could be used to side step any offer and continue to collect on the remaining amount later).

I get that they're trying to obtain as much money from me as possible but had a few questions on how I should proceed?

1) Due date: can they legally change the date like they did?  If they send a letter post-dated Aug 1/2, but due Aug 9, is this an example of them breaking any laws/rules for collection agencies?
2) Due to the unnecessary roadblocks they're putting in my way, do I have a recourse with the Ontario government or under the law?  Is there a particular Ontario government employee I should be bringing this to the attention of?
3) Who owns the loan and is responsible for it: the government or TCR?  I've seen both parties suggest the other when it was beneficial for them to do so (eg government loans don't expire; TCR excusing rules as "government mandates" yet no one seems to be accountable for issues like the unnecessary treatment I received yesterday.
4) If they date a settlement for $x.xx on August 1, would that hold up as a binding final settlement for the loan provided I pay that amount prior to the due date offered?

Thanks in advance for your help!