Social security glitch, have I been overpaid?

I know no one can give me a definite answer. Back in March my daughter's father passed away, we were told that she would be entitled to a survivor benefit, which was okay. The weird part is, I was told also that since I was her primary care taker, I would get a benifit for myself as "child maitnece". Sort of their way of paying child support? I'm totally confused, because later, we were told that I would not be eligible because her father and I were not married. Everything was okay with that, I don't have a problem with it. We received our second payment on the 22nd of June, and I went to check my account balance again and it appears they paid me again today. It isn't back pay because we already received our "back pay" payment of about 1500 dollars. I'm just confused. Do they normally mess up and pay double in less than two weeks? I would call them and ask, but my daughter and I moved to the UK and as of right not I can't call an American number from a phone here. I can't find any information online either, I just don't want to get in trouble for using this money if they made a mistake. Or possibly the first person we talked to was right and I am getting benefits as well... Totally clueless.