Employer not issuing the salary slip

Dear Seniors,
I am working with a growing manufacturing company working in this field from last 7 yrs .The total strength of the office staff is 8 and 30-40 no of labour is employed in factory.The company is proprietorship firm and credit the salary of employees through net banking . I have asked directly to the company proprietor to issue the salary slip. But he is not issuing the same and neither sharing the any reason for not issuing the salary slip ..
Please suggest and guide, what could be the reason
Regards,

Dear you have not mentioned location of your Office/factory? How we can help you? Please furnish all relevant details for appropriate suggestions from members

My office is located in Delhi.
Regards.

Hello,
You may write an application to the employer and mark copy to area enforcement (Govt labour Dept). As issuing salary slip to fellow workman is a mandatory statutory obligation.
Regards,
Gajendra Verma

Thank you for your opinion Sir.

The same issue am facing in my company,the employer said we will provide the salary slip while you relieving from this company. Is that acceptable and also they didn't give appointment letter.

Basically a pay slip is proof of what you are earning- basic, DA, deductions taxes etc.
It is mandatory to issue salary slips as per many laws of India: for example
If your establishment is covered under M W Act then you are required to issue wage slips to employees as per sec. 18(3) of Minimum Wages Act, 1948 & the Rules made thereunder.
Take up the matter with employer.If other employees are also ready to demand issuance of salary slip, join hands in a polite manner and ask for salary slips.
Last resort labour office can be approached.

what if its not a factory but a financial LLP ?

Issuance of payslip is a basic requirement.
It does not matter whether it is factory or LLP.