Product: Consumer Loan

I fell behind on a couple payments to Toyota Financial so I called an negotiated a payment extension based on what the agent told me over the phone. Later they repossessed my car for non-payment and when I called them was told that I was never granted an extension and if I had been a totally different process would have needed to be followed than what I was originally told. Toyota refuses to put anything in writing or even send me an email summary of what was discussed on the call ( I asked multiple times ) so while I was under the belief my payment was extended they continued to register me as not paying. 
When I called again after my car was repossessed I was treated poorly by every single agent and manager and each time the details changed which I was unable to track because again they refuse to send anything in writing. When I questioned why I never received a default notice in the mail they told me it came back unreturned, however, my mail forwarding is still in place so this is not possible. Further they did not send a notice to my co-signer even though they have sent him multiple statements in the past. Again they claimed it came back undeliverable. 
I had to pay hundreds in fines and over a thousand in past-due payments which I believed had been extended based on a phone conversation with an agent. When Toyota called me they consistently asked for personal information without identifying themselves which I identify as a phishing scam and do n't respond to. 
They have acted wholly unprofessionally and my credit score has now been penalized and I have had to pay in the thousands just to get my car back from a loan I had no idea I had defaulted on. When I mentioned that I was not sure how a payment extension works since I have never done one before they just kept referring back to the same " if you read your contract '' statement even though my contact would not cover a payment extension instituted during the life of my loan. 
I was repeatedly told that agents were not allowed to put anything from the calls into writing so when I did n't receive any email or letter noting the extension I did not think this was a problem. I do n't think it is right that a company can have discussions and make alterations to a loan without leaning any paper trail and then turn around later and basically claim that I am lying because I do n't have a paper trail of my conversation with the agent. The later agents and managers I spoke to refused to even try to reach out to the agent who had originally granted me the extension and instead treated me as some kind of criminal who willingly stopped paying off a loan which I had already paid somewhere in the range of 75 % of. 
Again the main issue is that they refuse to put anything into writing that was discussed on a call then placed the fault with me when I could not prove that the agent granted me an extension and repeated treated me as if I was lying without checking with their own agent as to if an extension was granted. 
It should not be legal for a company to deal entirely in word of mouth contracts without a paper trail especially since the original contact was obviously a drafted legal document.