I called back number (03) 8740 1922 rang once then gets disconnected automatically.

Same result here - disconnected on call back

I let the call ring out as I didn't recognise the number. I have to do a lot of that these days. When I checked my answering service they hadn’t left a message and there was no unanswered call registered. All the hallmarks of a scam or robo call.

Called when I had no connection Must be a call centre

I phoned back - rang once and was disconnected. One of those nuisance marketing companies.