(1)Subject to the other provisions of this Act, where any refund is granted to the assessee under section 270(1), and—(a)no refund is due on regular assessment; or(b)the amount refunded under section 270(1) exceeds the amount refundable on regular assessment, the assessee shall be liable to pay simple interest at the rate of 0.5% on the whole or the excess amount so refunded, for every month or part of a month comprised in the period from the date of grant of refund to the date of such regular assessment.