The notice period of 45 days may not be necessarily applicable in your case!
This and enactments applicable to notice period/pay in lieu of notice period has been explained in length in many threads e.g.:
https://www.lawyersclubindia.com/experts/Resigned-but-employer-is-not-supportive-520111.asp#.VM9_tS2qr5Y
The notice period is part of service conditions that is governed by various enactments applicable to the establishment/employer/employee e.g. ( Name of the state) Shops and Commercial Establishments Act that was enacted to govern the service conditions of employees working in such establishments, standing orders……….. These being enactments/instrument of law/statue…. enacted as per law of the land, shall prevail upon any private agreement/policy/rule drafted by employer and signed with employee e.g. appointment letter/contract of employment/HR policy/service rules and regulations/service agreement etc……………and any service condition that is inconsistent with such enactments shall not survive…….
Your Labor Law Consultant/Service Matters lawyer may opine that you are covered by the def. of ‘Employee’ and ‘Workman’….............................
In such case:::::: the notice period applicable for 45 days of service might be NIL........................and if you were under probation the notice period is NIL...............
If you are unable to handle the matter on your own entrust it to your labor Law Consultant/service matters lawyer!
Are you a member of any employee’s/Trade Unions::::::If NO would you mind posting ::;Why?
