It's only when things go wrong, which in my case always seems to be electronic goods, that you find the brick wall to bang your head against. I have now found that going through your own bank and getting charge back is the most painless way to deal with them.
Of course overall Aliexpress is a great source of goods at a fraction of the price you would pay in the UK, as long as you are willing to wait for delivery and don't get caught having to pay duty as has happened on a couple of occassions. You take your chance.