They did, in that if Origin had processed the notification and let you know, you could have prevented it happening. That is the basic reason for the 10 working days wait for a migration to take place. It isn't a period set by Openreach. It is required by Ofcom.
It has two stages. The gainer notifies you of what you are buying and other necessary information by letter or email, (you selecting your preference at order time unless they only use email and say so very early on), and the loser lets you know similarly of any final payments are conditions such as returning a router.
AIUI Origin could then have stopped the transfer at your request under Ofcom anti-slamming rules, GC7, Appendix 1, Clause 2(a)
and following clauses.
That's assuming you had not received any notification at all from Plusnet, as if you had then your initial action should have been to respond to that telling Plusnet to cancel it. If they refused then once again the above Appendix 1 clauses come into effect and Origin could cancel the order.
Unfortunately, as neither of them seems to have let you know it was happening, none of that applies. But it is the reason for the 10 days. Plusnet should have pulled their finger out more quickly once the error was brought to their attention, to remove the need for that wait and allow the Urgent Transfer sooner.
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