S. 220: Collection and recovery of tax-Stay-Pendency of appeal before CIT(A)-Refund-Recovery during pendency of appeal before First Appellate Authority cannot exceed 20 per cent of disputed demand without explicit approval of Principal Commissioner-Adjustment of refund in excess of 20% held contrary to CBDT instructions-Directed to refund the amount. [S. 220(6), 250, 270A, Art. 226]