Front Seat Belt Anchorage problems of the 1999 Ford Expedition

I took my Expedition to the police dept. To have my childs car seat checked for proper installation and was informed that the carseat could could not be used safely. It was their opinion that the place where the seatbelt pulls from and where the seatbelt fastens to are on different planes. We went to babies r us and tried several different carseats and none would work. Additionally, the seatbelts to not lock imediately, therefore, adding additional movement of the carseat. Please excuse any errors in this message. It is difficult type in this space and check for errors.