Verizon Wireless Would not honor deadline set by their employee Internet

I am writing to complain about the business practices of Verizon Wireless service.  They are located at 140 West  Street, NY NY.

 Specifically, I relied on information given to me by an agent of the company that was not honored.   Admittedly, the agent made an error in giving me this information.

 I was told that I had 14 days to change my mind on my purchase and told that this guarantee expired on May 24th, 2012. 
When I called in to exercise this guarantee (and was requesting to spend more money, upgrading to a higher priced product) I was told that I had been quoted 14 days from the activation date and the term and conditions, which I was told repeatedly that  I had accepted, started from the shipping date so I could no longer exercise my options.  Evidently the previous employee had calculated from the activation date in error.

 The first employee told me that he had no authority, but that I could talk to a supervisor if I was willing to stay on hold for 2 hours.  I accepted.  Two hours later a was connected to Joslin (#129775) who repeated the identical information as the first employee, and said there was no proof the wrong information had been given.  She said that the computer system would not allow her to honor the promise made by the other Verizon employee even if she wanted to.

It is my opinion that a company should honor promises made by their employees, even in error.  If it were excessively costly I would understand, but I only wanted to trade-up, paying them $135 to do so, and do not think it unreasonable that they honor the promise three days later on the day they had told me was the deadline. 

I also do not like the practice of being told I could appeal to a supervisor only to learn two hours later that she has no authority to remedy the problem.