First narrow down if it is your local tower or your account/device.
Does it ever go faster?
Take your laptop and device at least 10 miles away from where you are having the problem (drive towards a populated area or take it with you on weekend to work etc)... if you find your speeds improve then you have eliminated your account/device being the problem. If you find it is always the same no matter what tower you are connected to there could be a problem with the way they have your account provisioned on their network... call them ask for 2nd level or data card support and report the issue... let them know you are getting the same results no matter your location.
If it does get faster then you know your account/device is good, and it is most likely the tower or your proximity to the tower. Try different positions/location at the location where it is slow.
Sometimes just placing it near a window facing the tower can fix issues. I understand your signal is good, however, over the years I have learned that the signal level isn't always the whole picture. Sometimes your signal is reflecting off a geological feature that causes high signal but makes data re-transmit so much that it never gets up to full speed. If you find a different location inside the house/office/whatever fixes the issue you might look into adding an antenna of some sort, or getting a router that supports your data card, and then connecting to the router while it remains in the "good" spot for optimal performance.
It could also just be an overloaded tower. If this is the case since you are getting less than 300kbps you can call and ask for 2nd level or data card tech support and have them check the tower speeds (they have the ability to see rates on the towers) and have them file a report that the tower is slow. If it is overloaded it can take a while for them to fix... they need to add more capacity and they are slow to do this unless they are getting a lot of reports about it... have any friends and family with sprint accounts report it as well to speed the process.
I am not sure you could get out of contract, you might have a good chance IF the tower is overloaded since they advertise a minimum speed (used to be 400k now is 300k I think) and you are not getting the minimum speed. I have not ever dealt with breaking out of a contract with sprint, but have not heard of many getting out without paying the ETF.
You can sometimes see what is going on by popping your location into this website: »network.sprint.com
it will show you recent fixes or upcoming fixes.