Caller: "Jessica Bruce" from optus

a lady going by the name Jessica Bruce called claiming to be from Optus. she was offering 40% discount off my phone bill for the next 6 months because I was a loyal customer. She had my name and email address. But the email address she quoted is no longer associated with that account. She said she will enquire with her manager. I asked for her details and she gave her direct number to call back ( (08) 7077 4869) which is different to the number she called me on ( (03) 9316 9210). We ended the call.