Unwilling to return voucher

On 4 July 2023, I purchased two items from the Samsung e-store. I used a R10,000 voucher. Immediately, after purchasing the items, I decided to cancel one item and wrote to the customer email address (***). I asked that instead of refunding me, I be given a voucher for the value of that one item. Instead of cancelling the one item, Samsung cancelled the entire order, refunded me the small cash portion and now over two months later are ignoring my request to provide me with the R10,000 voucher. The call center agents are unhelpful, and my emails are answered with generic non-descript responses. If Samsung were not willing to return they voucher, they should have advised me of this.