comcast cable/internet service

my daughter is a student at florida state university in tallahassee, florida. she shares an apartment with a friend. to aleve utility expense confusion, she pays for the electric and her roomate pays for the cable/internet service. they both have computers and in order for my daughter to have internet access, we bought and installed a universal router/reciever and installed it. it worked fine for awhile and then stopped. my daughter called comcast, the network provider, for servicing and was told they would not come and service her router. they told her that in order for them to service her, she would have to purchase a comcast router/reciever for $150.00. i found that hard to believe. i spoke with a serviceman from my cable company and he said comcast had no right to refuse service since they were customers. my daughter also told me that comcast has a tendency to withdraw double the amount of monthly payments from their customers if they have automatic withdrawal. it happened to her roomate and several of her friends which caused an overdraw with penalities from their bank accounts. i would like to know if this is a legal practice for comcast to do. i will be visitein my daughter soon and want to have a working router for her to use before the semester begins. any help or advice would be greatly appreciated. barbara sypien, titusville, florida.