There are a few more things wrong with this casino.
The home page shows the Kahnawake logo, yet according to the terms they are licensed by Antigua and Barbuda. This is the display of false licensing information to the player, as one of these must be a lie.
The terms for this no deposit bonus are hard to find. There is no direct link to it from the promotions tab, where all bonuses BUT this one are mentioned and a link given to the terms.
Having found the terms, it doesn't seem there is much to hide, but they DO have an oddity that is at variance from normal industry practice, and that will catch out UK players in particular. It turns out that UK players who choose a lower worth currency such as the Euro and the Dollar are classed as "exceptional group", or in other words "abusive high risk players". This is more bullshit as currency abuse is players from outside the UK using our pound in order to get bigger bonuses. UK players choosing the Dollar are getting SMALLER bonuses, plus paying exchange fees. This is not "abuse", it is players choosing a default currency that is the most widely accepted throughout the industry. It is the strict rules imposed by Neteller and Skrill that drive this, as UK players have to choose one currency for the entire industry, and software such as RTG will only allow play in the US Dollar, with many EU based operators only accepting the Euro. Winner casino are ruling out many UK players with this rule, but many may not spot it till they have already registered their account. This variation from the industry norm needs to be made clearer.
The game weightings show there to be NO excluded games, therefore this should not come up as the next excuse for not paying the OP.
So, what is the REAL reason for not wanting to pay the OP?
Which is the REAL licensing jurisdiction, Kahnawake or Antigua?
As for the premiergaming site, it is riddled with "schoolboy" errors, even though it seems to largely stick to reputable casinos. It looks like it has been put together by a non native English speaker, and this alone will make visitors wary.
Outside of the casino industry, our Tranding Standards have issued guidance on how to spot something that isn't quite right, such as counterfeit goods. One aspect of this is to check for spelling and gramatical errors that indicate the instructions and labelling has been produced by a non native English speaker. The same can be applied to websites to judge whether it has been put together in the country it claims to have been.
Premiergaming appears to be a UK site for UK players, and so one would expect proper spelling and grammar throughout. Anything less sows the seeds of doubt, and is bad for business. Some of the errors just leap out of the page, so should have been easy to spot before making the content live.