Employer giving releiving order with wrong dates to hold my salary

Am a full-time employee of my current company since July 2016. I resigned on 31st of December and they releived and cancelled my pass on 11th March. But in my experience certificate/releiving letter my employer has stated that I only worked till 31st of December in order to not to pay for my notice period.

When asked about giving me the proper releiving letter with correct dates the HR told me to verbally say that I was giving KT/handover till March and since they cleared my tax till 31st December they won't give me the revised certificate with correct releiving date.

Is there any way I can report them to MOM that my relieving letter was not issued in proper date. I have a current ep in progress and I applied stating that I worked with my ex employer till March. There is a three month missing in my experience which am afraid will affect my current application too. Any advise would be much appreciated.

You should inform to your new employer in details. For MoM, they can see in the system when your ex-employer had cancelled the pass. It would last working day of your previous work. They must informed to MoM about this. Good luck

I am not sure if you are legally entitled to a letter stating from when to when you were employed by the company - check your contract! (This is not very commonly written down in Singapore, but most companies do issue such letters on request.)
If so, you could sue them into giving you one. If not, you are probably out of luck.
But as Surya said, MoM knows the correct dates anyway.