It is the primary responsibility of the company to get the form filled, duly signed along with necessary enclosures, and forward the same to the PF office. Once it is submitted and accepted, it is not the responsibility of the PF office to settle the amount. In case of any clarification, if they return the same, the company has to forward it again, duly clearing their doubts or attachments, etc.
Please inform the ex-employee that it was submitted to the PF Authorities on a specific date, duly providing the copy of the forwarding letter, and tell them that hereafter it is the responsibility of the PF office to settle the amount. The company is in no way responsible for the settlement or influencing the PF Office.
Once you inform them as above, they will not bother you. Let them go and contact the PF office and follow up. Nowadays, the PF office is sending SMS regarding settlement status. Therefore, you need not worry about this in the future. Also, please note that it is the responsibility of the Administration/Finance department to send the form to the PF Office and not HR.
Regards,