Calls and leaves long blank voicemails.. definitely dodgy.

Caller: reed trade fair eventor

This is number from Reed Gift Fair account team to chase you up payment.

Avaya messaging service
www.avaya.com/apac/product/avaya-messaging-service

Ask for Veyer box code. Spam.

Sydney, Australia number calling my UK mobile phone. Weird. I could hear some sounds at the other end, but nobody spoke when I answered the call.

Picked up, no one replied, then they phoned back ….. no one there.

I called back number (02) 8047 3500 reached voice mail but did not say from what company.

Called today and said they were Online Retailers Conference. How do they get our names and numbers. I said not interested. Can't find that number related to that conference so assuming it is scam

I called back number (02) 8047 3500 reached IVR saying from Avaya messaging.

Have phoned multiple times. I didn't answer the first few, but the most recent one I answered and it just hung up on their end. Definitely spam I'd say.