If Abbey tell you what it was sold for and when, I would probably accept this. You could go round and ask the owner politely, but IMHO Abbey are unlikely to risk providing misleading information that could subsequently be part of a court case; at least not information that could be easily disproved.(posted 8309 days ago)Again IMHO You can't sue somebody for harassment because they threaten you with legal action in what they view as a legitimate debt. You can, however, hold your ground and continue to write politely asking for the documentation to substantiate their claim so that you can consider it. A court of law would insist on them proving their claim if it went to court, and the Woolf reforms encourage both sides in a dispute to exchange information at their earliest opportunity to avoid the dispute escalating to the courts... so what you are asking for is perfectly reasonable. They are probably asking you to complete an I&E form, and you should politely decline... none of the information is factually relevant to their claim; its information they want to help them determine whether you have assets/income worth pursuing.
Just keep trudging along...