Can you have two defaults for same debt?

odd1out

First time poster but i've been watching in the shadows for ages! Can anyone give me a little advice please?

I have two accounts with Halifax one of which is in the hands of McKenzie Hall debt collectors. When i checked my credit report it shows a default with Halifax for £1082, but it ALSO shows a default with Hilco Recievables (who I presume own McKenzie Hall) for the same amount.

Two Defaults for the same debt? Surely not? Can they do this? The debt has never been sold on, to my knowledge anyway, i've never recieved any notification of this. I've sent letters to both Halifax and Mckenzie Hall asking who owns the debt and asking for proof, i've also asked for copies of the default notices as i never recieved these either!! I informed the CRA's that i wanted to dispute the Hilco entry as it was the same debt as Halifax but they have just wrote back confirming that Hilco have told them the information is accurate. Swines!!