I'm running a Counter-strike server and I want to change my upload speed.
Currently, I am a 1.5mb download and 256kb upload. I want to change it to 1.3mb download and 512kb upload. I called the cable company and they said that I already had the highest service and could not change upload speeds.

Is this true or is there a way to get higher upload speeds and maybe the telephone operator just didn't know

If there is, I would appreciate any help. Thanks!

Nope, your getting what you pay for. Some have been known to I know on cable modems to hack the firmware and bypass the limits but when I worked at the cable company, they would catch them everytime as most of the time the cable modems would give out after awhile on whatever they did to tweak them (you can imagine that they do test the modems when they are swapped out). So the cable company would shut them completely off, tell them why and pretty much made them use other services because of it.

So if you want faster downloads and uploads, upgrade your service, that's the easiest way.

Well you see, i dont want to get faster speeds. I want to degrade/slower my download and make my upload faster.. I already have the highest service my cable company offers.

It's not possible, you can't do that.
The only way you can increase your upload speed is upgrading your connection.