Taking advantage of consumer innocence

Icici direct provide a new scheme of brokerage charge to its various clients. I have also received an email on this as I am also eligible for this scheme. But we need to activate that scheme through customer service or by IVR call. The scheme is not chargeable. As I am eligible for the scheme I have started trading in ICICI DIRECT on 19th December and don't activate the scheme for my account as I was not aware of that. The brokerage they changed me is around Rs. 77k however it could be Rs. 5k under the said scheme. Rs. 77k includes 65k brokerage and 12k gst. On the very next day i raised this concern with the customer service. And awaiting response. Can I claim to revise the brokerage amount according to the said scheme on the background of innocent? Please help me on this. Regards,