advanced cash services They email me a letter saying they will report to IRS that i have an unpaid loan and I need to pay 300 by April 5. I only can use money pak and I did pay them. Internet

I recieved an email on March 29, 2013 stating that I have an unpaid balance of 663.00 loan. If i didn't pay it they would report it to the IRS and they will take my tax return. So I ask for an settlement and he said I can pay 300.00 by April 12, 2013. Then he sent me an email stating that I only can use an money Pak. So I went to CVS and got a money pak and he stated that he will send me a receipt saying that the account was paid in full and I have an zero balance. The number that he had didn't work, I been emailing him because I never received a receipt. i feel like I can rip-off for 300 and I want my money back. I dont have money to be giving away. i have 2 kids that i have to take care of.