DPD Uk Courier delivery service

DPD assured us that their services could be integrated into amazon to allow us a prime option on heavier items. Despite reassurance from DPD that the account is set up accordingly we are getting notification from the amazon onboarding team that DPD is not a recognised and accepted delivery option. Despite countless emails I am getting the same seemingly automated response. I am sure I have seen DPD being offered as an amazon shipping option so refuse to accept that it is not available. Does any one have any experience in getting DPD integrated ?