It's Westpac. start talking about home loan package and tried to sale insurance.

Several calls to landline & mobile. Eventually answered landline. Dwayne from Westpac asked if I'd received correspondence from them recently & if I wished to continue discussing the specific contents of that letter I would have to provide him with some security details not pertaining to banking but I don't have to if I don't wish to proceed - he'll call at another time more convenient.

Saying he is from Westpac. But I couldn't search this number on google

I called back number (02) 9155 7771 spoke to a woman who said company name is Westpac.