If it helps any, there apparently is a UK office of Yackie in addition to their 2 US offices(Florida and Delaware):
14 Hackwood Robertsbridge, East Sussex TN32 5ER, UK
http://www.yackiemobile.com/main/contact/
Even though the sim is Icelandic, Yackie has a physical presence on UK soil so this may give you stronger legal recourse.
Phones/Wireless Devices: Doogee S90, Isatphone Pro, Amazon Kindle 3G, SkyRoam MiFi device, Karma MiFi device, AT&T Liberate MiFi device
Sim Cards: T-Mobile (Mint), AT&T (Mifi device or Kindle), Koko
Satphone: InMarSat
Broadband US Wireless Data: AT&T postpaid, Sprint (Karma Mobility prepaid)
Broadband International Data: SkyRoam
VOIP: Skype