Business ProfileforBerkshire Bank

So I called a couple months ago to Customer Service and they gave me a fax number in an email one or the other. I forget to send the information in since I was the beneficiary on the account now yesterday I call that accounts closed and I'm no longer the beneficiary. Its been Wiped clean. I had called because I misplaced everything. They had also told me to write a letter and stuff with my information so they could get everything transferred over and that was two months ago. Now nothing! There is money left in that account and where did it go because they're saying zero. When I called a couple months ago, I told him I thought there was fraudulent on my moms account because when I got my mother, there is handwriting in the checkbook that did not match my mom and it was in the 1400s of the checks, but the checks that were in the checkbook were in the 1900s. My mom is *********************************. Her date of birth is ******** *** ****. This needs to be resolved ASAP because I know for a fact I was the beneficiary because when we called when my mom was alive, they stated it to us and when I called two months ago, they confirmed it And yesterday its gone. When I spoke to the Customer Service people two months ago, I want to say they said it was around $675 so where did it go? Why was my name taken off after she was dead?