UPS Part-Time Pension

This is my first post but I feel it is very important to all. I started here part-time in 1990 and was finally hired on 9 years later to a full time driver position. When I started cover driving a year later, it was explained to me how the pension worked for part time employees. If we worked 1500 hrs in a years time, we would receive a full years credit or 12 points. For all hours less than 1500, we would get credit appropriate for the hours worked. Recently, I have been trying to find out just where I stood on retiring. It has been brought to my attention that UPS will recognize only the first 750 hrs or 6 points worked during a year and anything over is gravy for themselves. This was not my understanding and this puts me way off track for retirement because 8 of my 9 part-time years were full 1500 hr. years. Can anyone shed some light on what I should do?