Samsung Buy and Get Promotions.....Vouchers do not work

Terrible Service At the end of 2019 I bought a Samsung fridge which came with a Buy and Get Promotion of R4000 in Mr Delivery Vouchers. Some of the vouchers did not work and I notified Samsung. It's been over 2 years and Samsung is not willing to honour the vouchers that didn't work starting that the promotion is over, even though they were noticed both my email and numerous calls during 2020/2021 and 2022. The manager, a gentleman by the name of Amin has been investigating the matter forever until last week his said he cannot help. Appalling service from a big brand. Last year I complained on HelloPeter and I was promised a swift resolution, however since then nothing has been done. For 2 years I was asked to keep sending screenshots of the vouchers that did not work, which I did but nothing was done about it