Filing Letter of Undertaking (LUT) in form RFD-11 has been made mandatory by the government as per rule 96A of CGST Rule-2017 notified by GST Notification No. 16/2017 dated 07-07-2017. Know all about the form and LUT here in the article.
Once form RFD-01/01A is filed, an acknowledgement of the same is available on the GST Portal. This acknowledgement is called as RFD-02 which also serves as a response to RFD-01. Here is the detailed explanation of form RFD-02
If your GST Refund is stuck and is not getting processed or is rejected, there are a few steps you can take to raise a grievance for the same on the official grievance redressal portal. Here is the step by step process.