After you file

Hello sir/Mam please i need your help about the same topic, i gave my information and my family, which is my wife and my son's informations to a tax preparer to do my tax for me and he did sent it last week and irs has already accepted but I just found out that the tax preparer didn't include my 18months old son on my tax, please what should I do ? I have been calling him but he's not answering and when he finished he told me he has added all of them, I only found out that he didn't include my son when he sent me the 1040 forms and I went through, please kindly help me