Purchase via Commission agents

1. My client is Mobile dealer and purchase mobile through e-commerce companies.
2.He make payment to e-commerce company via credit card of third person(i.e commission agents)
3.And after that he pays all the agents via bank NEFT/RTGS.

my questions are:
1.Is ITC available on this kind of transactions?
2.Is this transaction considered correct from a legal GST perspective ?
3.any section or judgement available for that?

kindly answer for my queries..
thank you