Cognizant — regarding a staff texting in whatsapp

Address: Coimbatore, Tamil Nadu, 641302

I'm vinothini from sirumugai. I have received messages in whatsapp today morning from an unknown number. While i enquired whom it's, he said that he is venkat from cognizant. When i asked the reason for texting me, he said that my resume got shortlisted & asked me when i can come for the interview. When i asked why did he message in whatsapp for this, he's telling that it's his senior manager's order to inform the candidates. None of the company staff will do like this. If my resume is selected, he should have mailed me about it. If he's really a cognizant staff, i need to know why does he behave like this. Didn't expect such a behaviour to call a candidate for interview. I request to take necessary action on this.
Venkat - [protected] is his contact number from which he texted.