You don't say how old the pc is, but if you have it on paper that it is supposed to be collect & return and you are within the warrantry period, you should be speaking to your Local Trading Standards Office. Normall y via the local concil.
AMD Radeon Adrenalin release date, new features, compatible graphics cards
Inside the iMac Pro - Apple's most powerful Mac yet
iMac Pro release date, UK price & specs
Comment nettoyer Windows et optimiser son PC gratuitement ?