Keep getting daily calls on my mobiles from this number, it's becoming harrassment

I recently signed up for a subscription to The Advertiser (SA newspaper, part of News Corp Australia).

I think I must have had a failed / half finished attempt at signing up, because this phone number called me asking if I was interested in signing up (I already did, in the end).

They kept calling me every single day for about a week, and would never leave a voice mail.

So decided to pick up and just say that I'm happy and hopefully they won't call me.

This number has called me twice this week and hasn't left a message. Now blocked. If it's important, leave a message.

Called, silent voicemail and then when phoned back it went straight to busy dial tone.

Blank voicemail
Called back - busy tone
Probably newspaper or bad dude

I called back number (03) 9452 6057 rang 3 times then goes to busy tone.

this is the australian newspaper about subscription.

Don't know who this is, but just had a call from this number. tried calling back, only got engaged signal.

Claimed to be someone from Daily Telegraph, they've called me 3 times today

I called back number (03) 9452 6057 rang 2 times then goes to busy tone.

I called back and it was busy, both times. Suspect it is a telemarketer or the like.

I called back number (03) 9452 6057 rang once then goes to busy tone.