BAD SERVICE FROM MULTICHOICE !!!!!!

Over 5 years ago we purchased a DSTV Walker which we have used when there have been power outages etc. It cost us R800 at the time. Just recently my husband switched it on as he wanted to be able to watch some rugby at work. There was an error message and we phoned DSTV - and were told that it does not "transmit" anymore and we were sent an email last year to state this was going to occur - well we did not receive the email. On further investigation after going on Live Chat - DSTV - everyone was sent an email with a R500 takealot voucher.... well guess what we did not receive the email and we did not get the voucher ...and I have asked for proof of this and guess what I am still waiting.... Is this right that we get treated like this by a huge company like Multichoice?