S.J. VAZIFDAR, J.

1. Respondent Nos.2 and 3 are the State of Punjab and the State of Karnataka. Respondent Nos.4 and 5 are the Excise & Taxation Commissioner and the Excise and Taxation Officer cum-Assessing Authority (ETO).

2. The petitioner seeks a writ of certiorari to quash two show cause notices dated 16.10.2014 and 05.06.2015, an assessment order dated 03.08.2015 and a demand notice dated 18.08.2015. The petitioner also seeks a writ of mandamus directing respondent No.3-State of Karnataka to refund the Central Sales Tax (CST) collected from the petitioner. The impugned order dated 03.08.2015 is an assessment order made by respondent No.5 (ETO) for the accounting year 2012-13 under section 29(2) of the Punjab Value Added Tax Act, 2005 (PVAT Act) as it stood at the relevant time. The impugned order dated 18.08.2015 is a tax demand notice directing the petitioner to pay a sum of Rs.55,21,230/- pursuant to the assessment order. The assessment order assessed the balance tax due at Rs.1,30,84,500/-. Interest under section 32 of the PVAT Act was levied and penalty under