As a valued customer, you could lodge your query or complaint through the following available options

1. Khatabook App (https://play.google.com/store/apps/details?id=com.vaibhavkalpe.android.khatabook) 
2. Khatabook Customer Service contact no.: +91 - 9606800800 or Email ID - grievanceofficer@khatabook.com     
3. Write to the Nodal Customer Grievance Redressal Officer of Khatabook at the following address 

Yogesh Pawde

Grievance Nodal Officer,

1203, 22nd Cross Rd, 

Sector 3, HSR Layout, 

Bengaluru, Karnataka 560102