answer the call no one speaks, hangs up after 15 seconds. Rang back got message service saying "our operators are busy and we will try to call you back soon" does not identify the company.

I called back number (07) 3153 1040 reached voice mail but did not say for what company.

(07) 3153 1040 rang my mobile 3 days in a row, no voicemail left. On day 3 I answered the call and they hung up without saying anything.