Magnamail is not actually a scam company, just exaggerating how likely their customers are likely to win anything useful in the equivalent of the "lottery tickets" or "raffle" they tell you that you will be entered into. You have to read the fine print well to see that this is just a marketing ploy. But, there are the occasional things that are worth purchasing and you will get those that you order or your money will be refunded.
Some products that Magnamail has does not work very well. I have found them to be reliable but it is important to understand that the "you have won" spiel is marketing. They don't say you are the winner of a decent prize by the way - so you might receive a piece of junk jewellery or the equivalent with your order for your trouble of returning the special number they assign to you. It is much like what Readers Digest do.