Probably too early for them. I found this to be a problem the other year. As with summer holidays we like to book earlier and earlier. The Bulgarians prefer to go at a slower pace and they won't - or haven't in the past - done anything about the next season until the summer - ie July/August at the earliest!
They take a while to respond. We fly out on Saturday and hvae booked with them and still awaiting the email confirmation they send a week before and its only 3 days to go.
thanks for advice, i have now had reply and they are doing packages for next year,starting in a couple of weeks hope this helps anybody else interested,cant wait for return trip to borovets : cheers paul