[RonBee]

Try:

It is with great regret that I am resigning from my present position as receptionist within your organization. As per our agreement, I am giving one week’s notice, effective from today’s date.

This decision is made as I would like to spend more time on my studies. I have truly enjoyed my experience at [company] during the past seven months. Thank you for giving me a chance to learn and to gain this valuable experience. I hope my resignation would not cause you much inconvenience.

Once again, I would like to express my sincere gratitude and thanks for the help and support that I have received. May I take this opportunity to wish you all the very best for the future.

Thank you for your kind attention, and I would appreciate if you could let me have a reference letter before I leave.

Yours sincerely,
[signature]
XXX