The terms seem pretty airtight to me... guess question is, did you book a non refundable "rate" that usually means it's also non cancellable and non changeable?

If you do call, select Malay language (most CSOs at the Malay line do speak English as well) as opposed to being routed to Philippines CSOs who're always "by the book" and don't lift a finger beyond what's been prescribed to them (from my experience).