Sorry to hear this. They are a very well respected company, and used by many forum members. I am guessing as they are very popular that phoning is going to be a case of letting it ring and ring as I'm sure they are inundated with calls, and probably an answer phone can't handle the volume of messages perhaps. As for emails are you certain you have the correct one? And that you aren't sending it to the wrong department, or it isn't mispelled etc - sorry if that seems obvious, but its a mistake I have made (with a different company) in the past so thought it worth mentioning. As for facebook, I have contacted them a few times through it, and even though I am not in the same country and so not buying a product from them, they have always responded and been more than helpful - have you tried this route?
Sucks that you are having a bad experience, and I hope it is resolved soon, but the posts I have read from happy customers over the years indicate that this is not the norm, and so I can't agree with your recommendation for others not to use them, though I can understand your frustration, and you can only go by your own experiences which haven't been great.