[inquisitor]

Today I received an answer from the Liechtenstein regulatory authority (Amt für Kommunikation), which confirms that United Mobile has interrputed service due to disputes subject to civil law. The case is under investigation by the Liechtenstein consumer protection, which as a branch of the department of commerce and transport, a public authority in Liechtenstein.
Meanwhile the district court of Liechtenstein, which is responsible for insolvency proceedings, has not replied to my fax, in which I asked if United Mobile is involved in such.
The Swiss Company Registry, which bourbonkiller mentioned, is of secondary importance, since the parent company is registered in Liechtenstein and so bankruptcy should first be filed there.