Incorrect Device on upgrade not replaced

I upgraded 1 of my contracts in March 2026, the phone upgrade was for the S26 256GB, Vodacom was running a promo, where if you upgraded to the S26 256GB, they would automatically upgrade the phone to the S26 512GB, an additional promo was if you were 1 of the first 10 000, you would get a fast charging charger. Within 3 days of receiving the phone, I call Vodacom to advise them that the phone was incorrect based on the Promo, they fetched the phone within 2 days, It is now been a month, with me constantly calling them to follow up with no resolution, They have collected phone, however upgraded my contract and are charging me for the new contract without a device. Every after sales agent I spoke with advise they will escalate the issue and keep me updated on progress. I cannot accept this service knowing the capability of Vodacom, If this cannot be resolve within the next 2 days, I want this contract reversed and my account reimbursed.