No consideration for passengers

Took bus from Cape Town to Pretoria service number GCBJ180 I was expected to pay for extra luggage which I didn't mind. However when I arrived in Johannesburg I was expected to remove and carry all my luggage from one bus to another bus. After I explicitly explained that I am physically not well and can not carry the luggage. Can someone please explain to me why I paid for transportation of extra luggage service if I am expected to move and carry it myself? Furthermore is Greyhound trying to let it customers with physically challenges not to use their services?