I also took a Wimax connection about 3 months back. I was on the 750/4GB plan. After about three days, I realized that I was surely going to cross the limit of 4 GB. So I called the customer service and was informed that I could change my plan and be saved. And then starts the nightmare, two days after I upgraded (Rs.1499/7.5 GB) the connection became more unstable than Karnataka government.
I kept getting the DHCP error and those stupid customer service guys had no freaking idea of what was happening and kept giving me some stupid commands that I know will not work.
So technically I was down for more than 3 days a week. Then came nightmare number two, the bill. The bill was for about Rs.1950, and all my usage added up to less than 6 GB and I was on a 7.5 GB download plan. So I asked them to rework my bill, which they refused, and when I said that I technically had more than 1.5 GB still left. They said that is not there problem, is it not. If I had the connection working, I would have surely made use of it or even if I had exceeded the limit I would have paid for it. But paying for service that you cannot use is just ###.
Whenever the connection was working the speed was awesome, but alas, it hardly works.
Reliance needs to fire the guy who head there Wimax department, Kill the guy who runs the technical support department and castrate the guy who handles billing, then might be they will improve.