I have a similar query - upgraded with Avios over the phone from SIN-LHR Club to First (35,000) maybe seven weeks ago, and the avios have still not gone. I did get a new 125- number a while ago so assume the ticket is now in order, just not taken the Avios. Travel is not until April
However, on outbound upgrade on the phone and Avios taken almost immediately
What might the issue be?