I haven't faced any problem with powertel.
Anyway try with some of the basic tips for faster and better internet connection,
* Check the Start up programs and remove the unwanted
* Maintain a Decent Space limit at Hard drive
* Check for Malware, Spyware and bots
* Clear cookies and temporary history files
* Close unwanted background tasks if any
* Reset the modem
* Check the wirings
* Browse with latest and updated browser
* Download using torrents
* Upgrade your hardware
Following these steps may fetch you a better result. You can see the difference in your connection speed by having a speed test before and after performing these steps. You can have speed test for free from http://www.scanmyspeed.com/
. You will definitely see the difference.