Hi @DufferTom Welcome to Community!!
Sam’s Club members can select Pandora Plus or Premium at a discounted rate for 12 months. However, that offer is only available to free listeners. Existing Pandora Plus or Pandora Premium subscribers will need to cancel their current subscription before they can redeem this offer.
Once you have canceled your subscription and it has expired, you can visit the Sam's Club site again to redeem this offer.
If you need help cancelling your subscription, let me know.
Thanks again for posting to community!