Panic over! Got a notification from UPS about 8am today, saying they were on their way.
Then, 2-3 hours later, the documents/answers from Pixmania that I needed to pack it (after 5 weeks of struggle!).
Hastily packed it, then rang UPS as advised earlier, as their tracking had said an address was incomplete, which had stalled the pickup.
(Eventually) UPS told me it was because I needed Pixmania's account number with them, for the courier to pick it up at no cost to me. Also that they were unable to find the transaction at all without it (I tried to say I would have thought it would be confidential, but don't know if she could understand).
Emailed Pizmania, who replied that I didn't need it (just the tracking number I already had).
By that time the only thing for Pixmania to do was abandon that transaction & start a new one. So Mark 2 probably starts tomorrow.
Today's events were a breeze compared with my saga trying to get answers from Pixmania's usual customer service people. It was a stroke of luck luck eventually getting a sensible person.