Jolie

We just got the receipts for my husbands case. On the receipt for the I-765 & I-130 his name is spelled correctly, but on the receipt of the I-485 there is an "O" instead of a "D" in his first name (it's really dumb they put 3 "O"s in a row!). It says to call the National Customer Service Center's 1-800 # if there is any mistake on the receipt. My experience so far with this # has been quite bad - every person tells you something different. This is why I'm a bit hesitant to call.... Is this a huge deal? Is this something we can change when he goes for his interview? Or should we call or write a letter? Has anyone else had this happen? We don't want to hold up the process or delay it.....

Thanks!!