Perhaps it was a test of initiative?? You must be able to get a number for the company somehow (directory enquiries, thomson, yell, their website??) and you said you know the callers name as you addressed your email to them - so just call and ask to speak to them - is the interview today? Did they say what time? If so, why did you need to call them - just turn up!!
Good luck - I hope it goes well - but they don't seem very professional if they have not replied to your mail, so make sure it's for you
EK x