1. Sir, you can approach the Regional Director or Joint Director of the Region/Sub-Region of ESIC to which your unit is attached, explain all the position in detail as to how you deposited the contributions through error etc. You can either demand for refund, or can also demand adjustment against future deposits, if due.
2. Since ESIC is a stuatutory organisation based on some statutory provisions, I think, there will be no problem for refund or future adjustment of excess contribution paid if it is found that the contention of the employer was correct.