I tried to redeem my Google Home Mini after upgrading to Spotify Premium. However the discount did not apply when I checked out on the Google store. Instead my credit card was charged so I cancelled that order with Google. Now when I follow the link from the Spotify email and try to put a Google Home Mini in my cart I get the following message:
Unfortunately, we couldn't add that to your cart. There are limits on how many you can buy.
I contacted Google and they told me I needed to deal with Spotify. How can I get a new promo code?