What you get on arrival is not a visa, it is a visa waiver for 21 days. If you want to stay longer than 21 days, you can arrange a visa waiver extension of 38 days at a cost of P3030. This can be done at any office of the Bureau of immigration. See here for offices near where you will be travelling
http://www.immigration.gov.ph/index.php?option=com_content&task=view&id=128&Itemid=72
The office in Ozamiz City is here
Bureau of Immigration Ozamiz Field Office
3rd Floor Rizal cor. Valconcha St.,
7200 Ozamiz City
Manuelito Kaamino - Alien Control Officer
Tel. # (088) 521-1581
You can arrange a visa in advance.
Here is the Philippines Embassy website, visa section
http://philembassy-uk.org/consular_VISA.html
It gives details on how to apply and shows the cost as £22
If you want to stay longer than 59 days, you can keep extending until you have been in the Philippines for 2 years.
The extension from 59 days to 4 months is the most expensive. It costs P4830 for the extension plus usd$50 for an ACR-I card plus P500 express lane fee for the ACR-I card.
Next extension from 4 to 6 months is P2830.
For more info, read this page of my website
http://www.bigjimsphilippinesexperience.com/visas.htm
Regards: Jim Sibbick