withholding last paycheck as ransom

I was employed by a local small employer office. I was employed for 6 years. I terminated my employment with two weeks notice. In the first week I was gone I receive a letter from my previous employer that I owed the company for time taken in January of 2004 when I was off on medical leave. I have an anniversary date of October 12 of each year since 1998. I was granted time in 10/03 for time accrued from 10/02 to 10/03 (3 wks) and I was paid in advance time that would have been granted 10/04. I did not leave the employment until 1/05 therefore, I surpassed the 10/04 granted anniversary date and began accumulating time to be granted in 10/05. The employer stated that I owed money from the time in 10/2004 and withheld my last paycheck (without stating that he was going to do so.) Is this legal since I worked through the whole anniversary year and began accumulating new time? What can I do? I live in Ohio and need to know where it is located in Ohio Law that he is in violation. What if a person owes a company loan of $1,000, can a last pay be withheld? What if an employer never paid overtime worked, because they didn't believe in it? What if an employer didn't grant correct number of vacation weeks when an employee met the 5 year mark and it was stated at the interview this would take place? Employer has a policy and procedure manaul but never distributed it to employees because he did not want to have to adhere to it.