Toyota Motor Credit Corporation, Toyota Motor Finance Corporation didn't apply an extension, now saying I am behind on payments Internet

TMCC has done it again, it seems.  I have been researching them, and it appears I am not the first person they have done this to, but I sure would like to be the last!  I bought a 05 Tundra in Aug of 08. First payment was due Sept. 30 of 08. 

I paid them on time every month, always on the 2nd of the month, until April 20th.  My payments are due on the 30th, my money comes in on the 1st, so I paid on the 2nd, I was told this was not an issue, as they have a 10 day grace period

I called, asked, and was granted a month's extension on April 20th 09.  I had paid my March 30th payment on April 2 09.  I asked for the extension because I had a new job, and wouldn't be getting the first paycheck for 4 wks, goverment job.  So I needed an extension. 

I was still catching up on bills and living expences on May 30th, so I didn't make a payment on June 2nd.  So at this point, I should only be 1 month behind, because of the extension.  Well, TMCC calls, and says I am 2 months behind!  I remind them of the extension, and they say it went for the march 30th payment!  I tell them it was already paid, on April 2nd.  They tell me that payment was returned!!  I then fax them bank statement for the month of April, clearly showing the payment, and yet they still refuse to aknowledge the payment, and continue to say the extension was for March 30th.

I called them every day for 3 wks, at first I was nice, then I got more and more frustrated, because they are clearly ripping me off!  They show an extension, yet it's for a month that was already paid!  They say that's impossible, and a manager proceeds to tell me I have been behind since I first started paying on the vehicle!!  So I continue to pay, but fall behind by another month because I ended up having to move out of my house, and get a new one, and that cost 2 wks of hotel costs and new deposit and rent.  So now, they are saying I am 3 months behind, which is really only 2, and are trying to repo my truck.  I call them and tried to work it out, but they are rude and refuse to work with me.  My sister was my co-signer, on Nov 30 she called TMCC and did a voluntary surrender of the vehicle, which I contested with TMCC.  With my co-signer backing out though, TMCC now wants nothing to do with me, even though I am continuing to pay on the vehicle to try to bring it current.  All I am asking from them is that they fix the extension issue, so I don't lose the $366 I paid them on March 30, but they won't budge still.  Do I have any recourse for this? I contacted 2 different attorneys, they said I couldn't do anything.  I find this hard to believe.  Is the consumer really this helpless???  I will never do business with TMCC ever again, due to their record keeping errors, their rude employees, and the loss of money and peace of mind I have experienced in this ordeal.  I am sure my truck will dissappear one of these nights, and I will have to pay the rest of whatever is leftover after they auction it.  If I could fix the extension issue, I would have enough to bring the vehicle current!!!