Unacceptable service and information for promotion

My husband and I really wanted to upgrade our tv. We happened to see that Samsung was running a promotion on their highly acclaimed QLED TVs. On the Samsung website it shows that when you buy a QLED tv, depending on the size, you will receive an in store voucher with a corresponding amount of money depending on the size of the tv. On the website no other information is provided, no T’s & C’s, no redemption info, no promo code, nothing. The only thing you can do is select the so called “participating” stores that have stock of the TVs on the promotion. So off we went to purchase our new tv at one of the said stores. At the store not one single sales person was aware of the deal nor did the actual Samsung rep in store know about the offer. We have purchased the tv and the store assured us we can come back to redeem the voucher if we can provide them proof of the offer. We have been given numerous numbers by Samsung to contact regarding the promotion with no answer or no information on how to do so. We have sent emails with no response either. No one at Samsung seems to know what the promotion is about and how we can redeem our in store voucher. This is absolutely unacceptable for a massive international company such as Samsung. This has caused us major inconvenience and we still have no answer.