Received Hilton Gold earlier this year courtesy of Macquarie Hilton CC. Have not spent $10k on the card as yet, let alone the $40k to get Diamond and saw yesterday that I was bumped to Diamond. Checked via online chat and it is valid until 31 March 2017, so not the next year and then until 31 March the following year (2018), which I understand is the case if you 'earn' it. FWIW have never stayed at Hilton - may now. Anyone else have this experience? Have some ideas on how it may have come about but not sure.