Mine is almost same case, shipped on aug 24. I had imported L3+ from bitmain. Bangalore customs is giving absurd reasons and asking for all the details that you mentioned and after providing necessary documents they are not replying. I am really looking to going to customs office and ask for details, they just cant keep items just like that . Its really really frustrating. I see no where its mentioned that importing miners is illegal in india and nor governament has sent any notice . Indian govt has no stance on cryptos as of now, crypto currency is still under assessment process.

However I got my apw++ power suply delivered without any problem, they charged around 4k INR as custom duty.

Please let me know if you find any solution to resolve this problem, i will share mine as well. I am already afraid about demurrage charges which would be around 10k already and god knows still how many days they keep it with them.