Its not a new plan, I am using 512 ul combo from 2 months, they have just reduced price and there is a big flaw with 512Kbps Unlm Plan. Every month around 12th or so Sync rate automatically changes to 256 and you have to get it changed by calling or emailing the sarkari babus.
Second go for 512 Kbps combo unlm and not just 512 kb unlm, (both r priced same)this way u get 500 free calls and your exsiting monthly rental gets waived off.
er yes i said 500 free calls , so it is the combo plan
and my friend has a 512 kbps connection and his sync rate doesnt change , thats a problem with your connection