Immediate resignation

Hi, please help me.

My story is, I worked for this company for almost 5 years and I submitted my immediate resignation letter last july 13, 2013 and the effectivity date was july 15, 2013.

Now the HR of the company is saying I am not entitled to get ANY benefits/privileges such as backpay for the reason of I did not provide my resignation 30 days prior to the effectivity date.

According to my contract, There is nothing about I will not get anything if I do immediate resignation.

Now my question is, is it true that I am not entitled to get anything because of doing immediate resignation?

Please help. thanks

You should be able to get the following:

1. Last Pay
2. 13th month
3. Tax Refund

What you will NOT GET

1. COE
2. Non-government mandated benefits