Expectation of any appointment letter from such a agency doesn't full fill always.
It is advisable to ask any of your family member or friend to discuss with owner of agency with facts of your employment/ demand
and ask to release your due salary with a humble request.
The issue of due salary can only be resolved with mutual understanding and agreement.
Hope above action may help you out .
with presenting facts/proofs of your employment and hoping for the solution.
Valuable comments from senior member's of the forum would be more helpful/effective.
In my opinion, as they are straightly denying for payment, you should first write them a letter mentioning that your salary for so and so period is pending and still not paid by them, in-spite of several reminders. Clearly mention that if your account is not settled within given time period then you will approach Labour Authorities.
Send this letter through Registered AD and also mark CC of this letter to Labour Commissioner of your area. Mention you complete and correct address on that letter. If still they don't reply you, you may approach Labour Office for recovery of this.
Hope this will help you.
For that they written that i am not a labour. They are paying me professional fees. On 7th Dec i refused to assignment so that free me from my duties which was wrong. They employed me as a professional but i have not sign any contract.