Product: Debt collection

On XX/XX/XXXX I contacted ( or they contacted me ), Portfolio Recovery Associates to begin to settle a debt I had with a XXXX XXXX Card. I was told I could start with payments as low as $ XXXX/mo.  When I agreed the individual I was talking did not set me up with the payment plan, he transferred me to another individual. She began asking me questions and said there is no way that she could do $ XXXX/mo it was going to have to be more. I began to tell her this is ridiculous its against the law to do this to people. Regardless, I reluctantly agreed to a payment amount of {$63.00} for 36 months. Significantly different than the {$25.00} for 36 months I believed I would be paying. 
I made a payment that day over the phone and set up automatic payments. The payment came out in XX/XX/XXXX ; however, the balance still reflected near the $ XXXX on the account to begin with. It did not reflect the negotiated price, I waited until the following month ( XX/XX/XXXX ) to see if it was something that needed to be adjusted in the system to reflect the balance that is owed at the negotiated price. 
I called on XX/XX/XXXX to explain my frustration over the fact that my statements did not reflect the negotiation and how it seemed odd to me they are collecting money from me with out telling what the balance was that I actually owed. I was told I would not receive this information until I had finished my payment arrangement with them. We went back and forth over how they expected someone to know how much money they are going to be paying over a designated time. I asked them to mail me an agreement of the settlement payments stating how much I was going to be paying over what duration of time. I explained how I wanted proof and how I was lied too the first time and I wanted proof we had an agreement and what it was incase they tried to pull something again, Needless to say this fruitless conversation ended with the individual I spoke with secondly ( I was transferred to the second person when the first person said she could not do that for me and I wanted to speak with her manager ) saying he would make sure he got out a letter stating to me that on XX/XX/XXXX I owed 33 remaining payments of {$63.00} and on XX/XX/XXXX I would owe 32 payments of {$63.00} and once these remaining  payments were made my balance would be paid off. XX/XX/XXXX I  called and explained I had not gotten my letter for my payments, the lady on the phone asked are these the payments for the settlement or the principal balance. I said, I am supposed to be in a settlement then asked, what have they been applied too? She informed me they were made towards the principal balance, and that I would have a remaining balance of the difference. I said go ahead and stop that payment for XX/XX/XXXX, I wont be making in. She said no problem give me a second to get that information entered. BAM! transferred to another person yet again. Who " promised to make this right, '' she would fix it, it was a mistake on how it was entered blah blah. I got her to stop trying and just cancel the payment. What could not be explained is, if it was an error, why wouldn't they have, Why didnt the other 3 individuals I spoke with catch it? Why couldn't they send me a letter to reflect my settlement balance amount or that I was in a settlement? 
I have been victimized through bait and switch tactics twice, once the first time with the incorrect payment amount agreed too of $ XXXX/mo and the second time by not entering me into an settlement agreement which would have left me with a {$0.00} balance and placing me in one where I would owe nearly {$1000.00} by the end. 
I am also greatly concerned this is common practice as it was never addressed by the others.