The mobile number of my provider, as stated on his (bare-bones) webpage is no longer valid. But he hosts my domain at some other company, which also lists a phone number on their webpage. Yesterday evening, I called them, and someone answered the phone -- who put me through to my provider.
I told him what was going on, he verified it, and told me that he would set the wheels in motion tomorrow (which is today) to get it fixed.
I also mentioned to him that I discovered that I hadn't paid him for about a year now -- I did not receive any bills, because I never wrote him that we moved. He was surprised by this -- he did not know that I hadn't paid for a year now. He told me he would calculate my bill and call me about it tomorrow (which is today) so that I could pay the outstanding bills.
My domain is still not available in the DNS, and I haven't received a call. I tried calling the hosting provider, but there's nobody there (which is understandable, because it's after working hours).
My domain is vital for the various communications I maintain with various people. I need to be able to receive email. When I call someone with a report that something doesn't work, I need that someone to take charge and fix things.
We're busy with a Secret Project, which relies on our domain and webhosting. This only increases the importance of the domain.
Maybe it's time to call it quits with the hobby-hoster and switch to a professional organisation that gives me more options for the same money. I just can't afford not to receive email -- which means I can't afford to rely on people who don't follow up on their promises and who are hard to reach. Which professional organisation would allow their clients to rack up a bill for a whole year, without even knowing about it?