Extend service contract

In the Service Acknowledgement is written that F5 may extend the end date of the initial first year Service Agreement based on either the product license activation date of the unit or 90 days from shipment, whichever is earlier.

We installed hardware on 29 october, so Entitled Service : 10-29-2012 - 10-28-2013. But license was activated on 9 January 2013.

How can we extend the end date?

Thank you for your reply.