If -(a)any person fails to make the return under section 70, or";(b)any person having made a return fails to comply with all the terms of a notice issued under sub-section (1) of section 71, or(c)the Central Excise Officer is not satisfied with the correctness or the completeness of the accounts of the assessee, the Central Excise Officer, after taking into account all the relevant material which he has gathered, shall, by an order in writing, make the assessment of the value of taxable service to the best of his judgment and determine the sum payable by the assessee or refundable to the assessee on the basis of such assessment.
