Can seniors request a refund if our travel agent bought us advamce Disney tickets at regular rate?

My husband and I are both seniors above 65. We booked the Disneyland package from from a travel agency in Manila, Philippines that is affiliated with an accredited travel agency in Hongkong, without knowing that entrance tickets for seniors are much much lower than the regular rate charged to non-seniors. Is it possible for us to request for a refund at the booth at the entrance of Disneyland, Hongkong? I read somewhere in the internet that this is possible. I would just like to confirm if this is true. Regular rate is HK$450, whereas Senior rate is only HK$100. I will appreciate your reply. Thank you!