If you are looking for a registered IELTS Review Centre and test provider in Davao then I would love to recommend the centre where I used to study and review before I took my IELTS Test which is called TSAA or The Study Aide Avenue.
It is located at Ponciano Street in front of Phoenix Petrol station and next to PNB bank. If you want to undergo an English review then the fee is P5k for 4 months and the IELTS TEST fee is P8,640. They have this offer that if you will pay the review and test fee in one then you will only pay P13k.
Review Fee includes Manual (GT or ACAD), reviewers for the 4 components, photocopy of test materials (examples), pointers etc etc.
For more info you may call them at 3006893 or visit their website. tsaaphilippines.com
*I got 7.0 OBS after a month of review. I hope this one will help.