Dear Sir
You can approach assessing officer of the concerned company and write him with all the available details that the company has deducted your TDS but not provided TDS certificate.
But before doing that, first check your 26AS. Check whether your TDS is appearing in 26AS. If it is appearing, you don't need the TDS certificates at all.
Further, you can also approach to sebi for these matters, if it's a listed company.
Please feel free to call/revert in case of any doubts
Thanks and Regards
Abhishek Dugar
CA CS B.Com