Vinted Inpost question

[Thingsthatgo]

I have been trying to find out how long I have to collect a parcel from inpost. Is it 72 hours from when they put it in?
The email says 3 days, but then to collect before 21st. If it was put in the locker at midday today, will it still be there in the morning of the 21st?
What happens if I can't get there in time? Can I extend the time?
(I've been called away unexpectedly this weekend).

I had something returned to me that wasn't collected because the buyer was in hospital. I can't remember exactly how long but we both thought it was a bit quick. If I was you I'd try and find someone who could get it for you

Thank you, I thought that might be the answer. It's frustratingly short!