Why did I recieve only a portion of my tax refund?

I filed my tax return and split my refund into 2 accounts. My refund should have been deposited today, However I only recieved the smaller amount in my savings account. The larger amount that went to my credit union isnt there. I called irs and it said money was deposited today. The bank said nothing went through and nothing is pending. Why would I get a portion of my refund at one bank but not the rest of it at my other bank? I do not owe any money to anyone, I am very confused. I used turbo tax and e-filed. Wouldnt the irs website or their toll free number tell you if your money was offset for any reason? I havent recieved any notices either.