Dear member,
How many employees work in your company? If not supervisor then to whom else you could have submitted your letter of resignation? This supervisor works to whom? Did you approach the superior authority of the supervisor? If yes then what did he/she say?
I recommend you hand over the photocopy of the letter from the supervisor along with the original copy of the resignation letter to the HR Department. Tell them that routing all the applications through the supervisor is just an office protocol. However, the supervisor does not have any authority to turn down the application.
If the HR professional also does not accept the letter of resignation then tell them that you will be forced to send the letter by Speed Post. The date of the resignation will remain valid.
Thanks,
Dinesh Divekar