Indian Railway Catering & Tourism Corporation [IRCTC] — excess gst amount

Address:	600001
Website:	IRCTC Canteen PARK STATION CHennai

Dear sir/madam
I would like to inform you that i had my breakfast on chennai park nstation canteen which was in under control by irctc, they give me the bill with 12% of gst when i enquired about the 5% rules they simply said the system didn't upgrade and they refused to collect the money with new gst rate.
I wanna ask that a day went passed now almost half of the second was also completed till they are collecting 12% gst because of their (Irctc) system upgrade problem, i wanna know what happens to the excess 7% money that collected by the irctc from the last two days? Where it will go? Did they return my money back?
I want justification from you personally. So please do the needful