That was my issue and as per Web Chat Support with Spotify, the stock has been exhausted and promotion has been ended on April 17th.
at 11:35, Apr 30:
But, the offer has already ended back in April 17, 2019. Please take note that the expiration of the offer can change as it's only until supplies last.
Unfortunately, the stocks for the offer has been maxed out already
We are out of luck, and we downgraded for nothing. In my case i will keep my personal plan and will not return to a family plan. I may cancel and switch to Youtube music subscription anyhow and buy the home mini on a discount somewhere else.
I have been having the same issue and none of the links and pages work for me. I get to the registration page and I click the register now button and I get sent to the main Spotify home page with no offer in sight. I would like to be a part of this promotion seeing as I've been a premium member for years now. It should not be this hard. Not impressed to be honest. I hope you can help out. It would be greatly appreciated.
The GHM promo ended earlier than expected, April 17th, so those who didn't applied before that day are highly unlikely to receive the link/code to redeem the speaker, I would even be concerned for those who have received the link and haven't placed the order yet.
And here we're all Spotify clients, so if the actual Spotify customer service can't solve this for you, you probably won't find the answer you're expecting here.
PS.: Post edited to modify the date from May 17th to April 17th, thx for the warn Flynch3211.
From reading other comments it seems to apply to both, those who didn't click on the link prior to April 17th and those like me who had a Family plan, swtiched to Personal plan only to discover that the links and promotion ended prematurely due to stock ran out fast.
I'm sure they will have similar promotions in the future, just last night in Canada the Google home Mini at Costco was $49.99 which isn't all that expensive considering.
Also Spotify released their quarter results this week and looks like this promotion of a google home mini increased their paid users too. I can only be hopeful more promotions will come, until then i will remain a personal plan of $9.99 and not go back to family plan.