Ic, thanks a lot for the explanationThe processing agents, Premier Tax or Global Blue are partners chosen by the merchants. How the service fee is charged which results in no getting the full VAT refund is also not something we as customers can decide. For cash refunds at some airports like France, there is commission charged as handling fee per refund form refunded by the cash refund agent. My personal experience in Paris CDG in 2013, 2014 and 2015 tell me that there is no consistency in how much is being charged as commission and refund from which merchant does not require a commission.
Really help me as a first time travller
Thanks again