I have been working for Google Registry for 8.5 years now, and am the TL/M of the team. But I was not relying on memory here (how would I remember the particulars of one single domain name out of millions, especially on the first occasion it is ever coming to my attention?). I simply don't understand the OP's claims given that I have confirmed in our system that the domain name 'forum.dev' is and always been premium and was billed as premium at the time of initial registration.