Samsung offers promotional gift but doesn't deliver on its promise

I received an email with a promotional gift from Samsung stating if you buy the S20 FE within the promotional period you will receive free earbuds and power bank. I purchased the phone on contract at Cell C two weeks ago. On the same day I used the promo voucher code and tried registering for the gifts. Multiple times it said that it cannot be loaded the serial number is a duplicate. I sent two emails to Samsung with only a response to the first email in which the advise did not work. I called Samsung customer care the agent couldn't assist and said she would escalate my query and was promised someone would call me back and now two days as passed with no help still. Is the promotional gift a lie? Is it false advertising? Why can't I claim it? I have attached my invoice of purchase on my email and noone at Samsung wants to assist me so I can get the gift which actually is essential to the phone as S20E does not come with buds or a earphone capability. Please can someone at Samsung HELP!!!