Its franchised by the local cable operator and if he happens to be Ahle then you had it. BBNL does not have any control over him and he is not bothered to give proper service. Internet is like a golden egg for him, he will only think of milking it and cannot think about the customer or anybody else.
They promise you 25mbs collect 1125 including tax and then you check your speed on speedtest.net, against their gateway the speed will be 25mbps/5mbps down & upload speeds. Check against other servers it can be .12mbps/5 mbps to 2mbps/25 mbps.
Basically your local cable fellow will collect money from you and does not pay to BBNL, which will restrict the bandwidth and data to your cable operator. This will lead to you not getting the bandwidth for which you are paying money for.