"3g mobile networks expand and contract depending on how many users in the area, causing the coverage to people who had good coverage before to reduce - so perhaps that."
Now we may be getting somewhere. The Optus Shop in Nambucca was a "pop up". The representative manning the shop was very knowledgeable yet was not directly employed by Optus. He had been in the past and therefore understood their products and services. And his brief was simple. Sign up people who are not happy with Telstra.
Yes, he had my IMEI as my main concern was coverage.
Surely Optus would not have "upped" its coverage during the pop up shop period and then abandoned the area after a maybe not so successful marketing campaign?
All I am trying to do is make sense of the sequence of events.
Great news ☺️