State Bank Of India [SBI] — unknown acc access

Address:

15, Neethipathi rajasekaran street, Sivankoil opposite road, Sivagangai, 630561

I have received an SMS from sbiinb stating that" you have made two invalid attempts for my username on 22/03/2018 9.18 am..you are left with 1 more attempt and your access will be locked for a day post 3 wrong attempts" . But I haven't tried logging in and I have never stored my username on mobile or pc.. then how come someone know my username, is it possible for them to find my password too?? What else should I do now???