Yep, others are reporting the same from various C & Collect points no longer offering the service.
I believe as problems can arise, some stores are simply stopping this service. People arriving too late, they have 7 days to pick up an item, any longer , and the store can dispose of the item as they wish.
A store near me has stopped being a collection point as near fights were happening with staff and customers when items were not brought forward , the timeline clearly explained when to collect, but not followed.
The above of course may not be the reason. When you can, pop into you local Sainsbury / Argos point they'll explain if and why they are no longer offering this service.
@josley