Have received a call from this person claimed to be from Telstra and wanted my banking details

Just got the same call, didn't identify themselves as Telstra and came through on a weird number.+0293683808. I am waiting on a Telstra refund but I know I gave them the correct information. Haven't called the 1800 number yet. It's looking suspicious!

I received a call from ? Telstra asking for my bank account details in regard to a payment refund
I was then asked to call back on this 1800 number to verify they were Telstra!
The message said " please hold the line as dealing with other customers"
They didn't identify themselves as Telstra!!

I received a call from ? Telstra asking for my bank account details , some of which he had but not all was correct!
He then asked me to call back on this 1800 number, which I didn't to verify the call