As a follow up...
Following advice from the seller, it appears that an IIS member failed to indicate on the listing that a PM had been sent offering to buy, prior to my PM offering to buy.
The seller failed to respond to my PM indicating that I was not the first to make an offer, thus leaving me in the dark.
A communication failure that has left me feeling, to my mind, justifiably aggrieved!
Maybe I'm just an old grump, but the topic is still valid!
This thread may lead to positive outcomes...
Cheers
Chris