Cancellation of insurance policy (problem with 15-day free look policy)

Unfortunately I was a fool to get an insurance policy from Phil Prudential. It was last June 25, 2013. That agent gave me misleading infos and promises. July 10, 2013 i went to their office to cancel my policy armed with my letter but they denied saying I'm past the 15-day free look. I was confused and insisted that that day July 10 is the 15th days so I am still with-in the free look. I need your help badly. They said that they can cancel my policy but i have to pay the 64,000+ in my account. I called a lawyer of my sister but not familiar with insurances and after my call they associate said that she will try to get approval from the management. I had to make a new handwritten letter at that same day in their office and asked her to sign for my copy. I will be leaving the country within 1 week and so I needed to fix this atleast be able to get a SOA with "cancelled from inception" before I go.

This 15-day free look policy is my only chance.

Thank you