Not sure how to make arrangements with collection companies

I've spent hours upon hours (and days and weeks) scouring the web for advice, and I'm still just unclear on what I should do in my particular situation, so I hope someone might be able to help.

Background: I went back to school in my early 30's to get a graduate degree (currently half way through, so I don't expect income for 2 more years). After 10-15 years of great credit history, for various circumstances I made a few late payments, resulting in my APRs immediately jumping up from lifetime fixed rates of 1.9% and 3.99% to default rates of 22-29%. The minimum payments also jumped way up, to amounts that were literally impossible for me to pay while in school. I contacted them and indicated that I fully intended to pay my debts in full and tried to get the APRs lowered, and when that failed, I tried to enter a payment plan, but I apparently naively gave them too much information about my temporary minimal income due to being in school (they said you needed a certain amount of income to qualify for the hardship payment plan arrangements), and shortly after having called them to try to make good on these two accounts, both appeared on my credit report as "charge off, bad debt". I called the CC companies saying again that I had full intent to pay my loan in full, and had only asked if they could lower the APR and minimum payments similar to what they had been before, but they said I couldn't deal with them anymore because now these other companies were in charge of the accounts.

So, now, I'm baffled about how to go about making a payment arrangement with the companies currently 'handling' my accounts. I'm now unwilling to talk to them on the phone after stupidly giving them a payment over the phone when they promised that would "bring my account current and prevent charge-off" This didn't change anything as the account was in fact charged off or. One of the companies is Creditor's Interchange (from my Chase account), and the other is United Recovery Systems, LP (my citibank account).

So here are my questions/concerns:

1) As far as the "pay to delete" arrangements I've been reading about, is this even relevant/possible for my case, since the "charge off/bad debt" was put there by the original CC companies, which I apparently can no longer deal with or pay? The two collection companies I mentioned haven't put anything on my credit reports yet, so there is nothing of their own reports to delete/retract, unless they can work with the CC companies to arrange for a pay to delete?

2) Is there any precedent and/or possible way for the CC to 'take me back' so I can deal with them (again I'm happy to be responsible for the full amount, just can't afford the 30% APRs and super high minimums). Again, I'm guessing no, if they 'sold' the accounts.

3) Despite my desire to pay the original creditor the full amount I borrowed as this is only fair, it totally bothers me to pay my original full amount to some totally different company who may have bought my loan for half the amount or even less, giving them a huge undeserved profit and leaving my credit report besmirched with the 'charge-off/bad debt' even if I actually ended up paying the debt in full after all! Seems totally unfair. (Unless the charge-offs could be deleted completely from my credit report, which again, I'm not sure is possible?)

4) Off all the sample template letters available online, which would are applicable and recommended for my case?
-Pay to delete?
-Verification of loan? (the CC companies told me which collection companies were now in charge of my loans, so I know they are 'valid')
-Request for documents so that I know how much they bought the loan for, so I can pay them a fair amount (if there's no way to pay my original CC company anymore)? I don't mind them having a reasonable profit for their risk, but if they bought the loan w/o my consent or knowledge for like pennies on the dollar, I'm just not okay with them getting 100% of the amount that is truly owed to the CC company.
-A payment arrangement offer letter?

One other note - I can't do a bulk sum settlement, as I simply don't have any bulk sum I can pay. I have no choice but to pay a monthly amount.

Thanks very much for anyone who can give me any advice on this!