Unauthorised charges

I have received a mail on the date 21st mar'18 from SBI that i am being charged for a transaction in consideration with Google miniclip apart from this i dont have any data and even the bank has denied to support for this concern as they said it is beyond their bound.What should i do?
Please help me out with this issue. I was previously charged in 2017 jan with two transactions specifying the same with amount ₹300 and ₹60.I requested a query in Google support even they are unable to help me.
I cannot find way out through this.
Please help.