Front Seat Belt Webbing problems of the 1998 Dodge Stratus

Rear shoulder belts was beginning to fray under normal use. Right rear shoulder belt was fraying more than the left side, equal use on each side. Dealership informed consumer they cannot repair at no cost to consumer because it was no longer covered under warranty. Please provide any additional information/attachments.

We have problems installing a carseat in the rear paasenger sides. The shoulder straps do not lock, causing the carseat to flop around. Trying to install a toddler carseat was impossible due to the seat belt not being long enough nor would it lock. We have called the dealer in our area several times to help find a solution and they were not able to provide us with any information on how to fix it. We need a way to install the carseat backwards and can not do so.