GMAC Financial Claims told husband, Gap Insurance covered the difference of total loss claim/Insurance deductible Minnesota Internet

Car was total loss. WE did every thing we were told to do. Per the Progressive Insurance company. We also contacted GMAC FInancial. They told us not to pay the monthly payment; due to the accident, prior to due date. That they would include that in the final total. The Insurance company paid all but 1300.00; we asked about why?Insurance deductible. We were told by GMAC Financial; believe it to be the claims department; that not to worry, the gap insurance would cover the difference. Now we are being harrassed that we owe it by the credit department. We have copies of everything including the letter from GMAC to Progressive releasing the lein to the Insurance company and saying it was satisfyed. Yet , they are telling us , we still owe; Now it is on our credit report. These departments do not communicate. There are so many departments and different locations. I quess it will take us to get an attorney to get this straightened out. We feel we should be compensated for the defamation of character as well. We would love to hear if any others have experienced the same and was it resolved and how? If not, can a attorney help all of us ?
Thanks for listening.

Mary
Cato, New York
U.S.A.