[mothered]

I already did couples of EB for different amounts.
I changed all contact and address info except payment method which was the same in every EB case. And now I am wondering if they can start any investigation for every EB or even connect all each otherwith police/bank

They won't Investigate just for the sake of It.

If It triggers a high volume of refunds, Irregular spending patterns etc, that's when they'll look Into It further.