As per Section 37B of Central Excise Act,
CBEC may Issue such orders, instructions and directions to the Central Excise Officers as it may deem fit,
For uniformity in the classification of excisable goods or with respect to levy of duties of excise on such good
and such officers and all other persons employed in the execution of this Act
shall observe and follow such orders, instructions and directions of the said Board:
Same is applicable under Service tax also as per Section 83 of the Finance Act
Hence if CBEC gives order for Service tax applicability due to which
Excess service tax has been collected
Or
Service tax which were not due was collected
Then also he has to pay such tax to Central Government.
However, no interest will be calculated in this case if
Service tax is paid within 4 days of such order
And
no right to appeal against such payment at any subsequent stage is reserved.
However, if amount paid and no appeal filed,
the interest shall be payable on the whole amount, including the amount already paid.