LTR 2644C for 2023 Tax Refund

I filed my tax return in February 2024 and was supposed to receive a refund, however the IRS keeps sending me letters that says they need more time. This last one I just received today states: " We're waiting for your tax account information to be available on our computer system." They provided a phone number if I have questions. I called the number but it was a robot that gave me no useful information. I just want to know what is happening. It isn't a large refund but we need it to make it through the rest of this year. Please let me know what is going on.