Source:
https://scmp.com/article/380938/stamp-disapproval

Stamp of disapproval

With the recent changes in the cost of both local and international postage, one would expect Hongkong Post to try to make the new values of stamps freely available. My usual source of stamps, 7-Eleven, is now always 'out of stock'.

On my last trek to the International Mail Centre in Hunghom I was initially told they, too, were 'out of stock' - it was only my indignant response that eventually persuaded the staff to search a back room, from where they finally turned up these basic items.