The IRS will not acknowledge receipt of a tax return. For future reference, any time you mail a tax return use a tracking service provided by the US Post Office with return receipt requested so you will know that the tax return was received.
Only the IRS and your State control when and if a Federal or State tax refund is Approved and Issued.
About 4 weeks after the tax return was mailed you can check the status of a federal tax refund on this IRS website - https://www.irs.gov/refunds
