It depends on what those two orders were, and why they attracted the attention of Fair Trading. (not Customs?)

If you were ordering a huge amount of stock, or restricted items, then there would be issues importing it into the country... and for those sorts of things, you do need to do your own homework and not just trust the word of a 3rd party business.
Do take note of what they tell you or advise you, but always double-check everything.

For me, I've never had an issue, and I've never had any other business communicate as much as these guys do. (it's almost like being spammed, they keep you that up-to-date with things)
And since the business has been operating for about 8 years, I can't imagine they are that bad.