I had an email 4 hours ago offering Google One free for 3 months, as a little gift. When I click on the link I get an error page with the Google One logo and this message "It seems that you have used up all your allocated codes. Please contact your account manager for more information."
I'm having the same problem too, it has the exact same message.
Also, if you look in the small print on the bottom, it mentions "This Google One membership offer (“Offer”) provides you with subscription benefits at no charge for a period of 6 months from the day you redeem the Offer (the “Offer Period”). "
This contradicts the original message: "So, here’s 3 months of Google One, on us.".
I think the people in Marketing (?) who pushed this out made a few mistakes...l
I am really sorry to hear you're also having issues taking up the offer. Is it involving some form of activation code that has 'expired' or is it just a case of you're offered the free limited time membership if you apply via a specific link and it's failing?
Also in regards to the duration, I will feed this back to the relevant teams and I am really sorry.