Hope you are doing great,
Manisha this side,
>>First of all, let me tell you that getting trademark is mandatory to have in case of private label product now.
See you can only protect your brand name by getting a trademark. Once you got trademark with your brand then you can send that document to Amazon and ask them to remove all the products listed with your brand. Amazon will also remove all the sellers from your listing as you only own the trademark.
>>See you can get TM within a month in most cases in just a week. For registered mark, you have to wait for a year. So I would suggest you to get TM immediately and if you see any seller selling your brand of products then you need to inform them that they are violating your Trademark Rights.
I would suggest to get a letter from your CA in which you can mention that you own the trademark and when you have received it along with your trademark number.
In this letter ask CA to mention all the clauses which one is violating when they are sending your brand of the product without informing you.
And upon any TM violation case, you can directly send this letter to the seller and threat to Sue his, understand this, as per Indian laws once can’t sell your TM of product and he will be fully liable for all the damage he is making to your brand.
In nutshell, if someone come under your listing then you can send him/her a letter which you got from your CA and imp thing is that use your trademark logo on product image also.