Closes account for no valid reason

I sent my sister a birthday gift in form of cash only for this complaint to put my account on hold and eventually close my account without a valid reason but a generic email saying that they close accounts if they suspect suspicious activity. This was my 2nd time using them and the first time l had sent the money successfully although then it was also a head ache because l had to follow up for over a week or so for the money to arrive to my sister in USA. Despite me adding all of her details she never got the notifications.