Rear Seat Belt problems of the 2002 Toyota Sienna

I bought a used Sienna Mini van from Toyota in MD with 55. 000 miles on it with all the warranties. When we went to use the rear seat belt on driver's side we noticed it would not retract. We took it to dealer ,and after having it for a few days they called me and told me that the rear seat beltwas not under warranty, and it would be $ 500. 00 to replace. Then the the mamager for the parts department caled me, and said that they will cover half the bill. I declined since we never used that seat belt . Then he told me that he would talk to the used car department about covering some of the cost he has not retorned my calls and ehen I go into the dealership they told me he was out sick. Were execting our 4 th child and we needed a working seat belt so we had the option of using the rear seat belt since we still were making payments on this Mini van. We also had a mid seat that seemed to be loose, and the part number they gave me was wrong . Can you help me with this sincerly , a am aconcerned mother.

Rear sear belt buckle refuses to latch. A child car seat cannot be installed in this seat.