what do i do?

ok so in 2004 i attended sequoia inst. for auto mechanics 4mo. into the class i had a test for a final grade in my engines class( which was to pressure test a coolant system. i went to the tool coral( where the school is suppose to check out tools and return when finished) and i tried to check out a pressure tester. I was told that a student(not me!) did not return it. therefore i failed my test.:mad: 4500 students and only one tester?!
then a mo. after that Corinthians the owner of the school decided to change change the name from SEQUOIA to WYOTECH keep in mind i still had about 9mo. left. i was told to study WYOTECH book take WYOTECH test and wear WYOTECH clothes. Yet recieve a SEQUOIA diploma! why would i want a diploma from a school that no longer exists?! anyway, i dropped out of the school o not to mention i had a teacher that my mom had problems with when she attended because she was a woman! he found out who my mom was (by last name and discussion) and started in on me! so to cut it short i was unhappy and felt the school failed to hold there end! 6-7 years later i getta call from collect COLEECT CORP saying i owe on a salley mea loan that i never took out. i asked them to send proof they said ok. every two weeks for the last six months i getta call with same conversation! no paper work! keep in mind i called SALLEY MEA and they said i have no account with them! there trying to charge me $3000! are there any suggestions on what i can do? ANY HELP IS APPRECIATED THANKS IN ADVANCE!