I had a Broadband connection of plan 750. I gave an application on 24th march 2010 for change of plan from 750 to 500c+ & got a receipt of that & being told by the Customer Care Executive that the rule is, if the application is given on or before 20th of the month, then the new plan will be activated on the 1st of the next month. & if application is being given after 20th of the month, it would be activated next to next month. According to this my bill for the month of April should be the 750. But I got a bill of Rs. Rs.9795. Please help me what shall I do?