A quick internet question.

I am only getting about 140kbs a second on average while downloading. I checked my internet providers website which is frontier and they don't offer any plans that slow in my area. We pay around 30 dollars a month for internet and on their website it says that should be giving us up to 5 MB/s. I went to talk to a support person and they told me something along the lines that the cable in our streets are too old and crappy to provide those speeds and the companies are too cheap to replace them. However, we are still being charged 30 dollars a month for internet speeds that they cannot provide. What can/ what should I do. 30 dollars a month is a rip off for what we and I want to know if there is anything I can do about it.