Fed up with the it dept.

I think, you should again upload a re-rectification request.

What is the time within which I can do so?

Is there a time after which the IT dept will put a stop and say .... "nothing doing, you pay up ...."

Also, should I write to the deducting company PF trust to look for discrepancies, if any? (even though 26AS mentions it alright)

Thanks.

As per the meaning assigned to the terms used in Form 26AS, "F" denotes Final.

It conveys that there is no mistake on the part of deductor and the assessee can take the credit.

Before that time comes, when income tax departmet will give its final order,  definitely, an opportunity will be given to the assessees of being heard.