Why are my hours disappearing so quickly? I haven't used that many hours?
You are likely on a shared network where someone else on your network has used up the hours. If this is the case you should speak to your service provider and ask them to give each connecting user a unique public IP address.
I think that you bought 1 month ago at that time hours for 30$ or something, that's why it got removed from you, as it gets removed even if you don't manage to use it within 1 month