PMPL Broadband - World's Worst Service

Today I take a connection from PMPL Broadband, their homepage URL is (http://www.pmplbroadband.com/) (user name - ar_bs), Haldia_Jet Silver Economy, they committed to give 512 kbps. But their bandwidth is not even close to 150 kbps, worst customer support, I have called their number 7 -8 times and only got them once and their reply is very unprofessional. I am a renowned webmaster in different forums using Internet for more than 10 years, now they telling me I don't know how to calculate the bandwidth. This may be the first and last day of this service, I will ask for a refund, lets see what happen. But I can assure you one thing if you want a worst service just take a package from them, you will get the "World's Worst Service".