I am dissatisfied with the appellate authority's order on my GST dispute in Kolkata; what is the next level of appeal available to me?

Under the CGST Act, 2017, the appellate hierarchy proceeds from the Adjudicating Authority to the Appellate Authority (under Section 107), then to the Tribunal (under Section 109), and thereafter to the High Court under Section 112 if a substantial question of law is involved. The appeal before the Tribunal must be filed within three months of the Appellate Authority's order, extendable by one month. If a substantial question of law arises, you may appeal to the Calcutta High Court within 180 days, extendable by a further 180 days. The West Bengal Premises Tenancy Act 1997 on SGST appeals may have corresponding provisions. The Supreme Court is the final appellate authority under Section 113 if a substantial question of law is certified. Legal representation by an indirect tax advocate is advisable for complex GST appeals.