Hi Members of the Forum, I understood something wrong from DHL-Express, the topic is so difficult and confusing, the real fact is:
Quote from DHL: "Once the shipment is above Php 50,000 customs will treat this under formal entry which the Consignee here in Philippines is accredited as importer that’s why we need an affidavit of ownership to request to file under informal entry cause this is for personal use but still subject for duties and taxes like what happened to your shipment now and customs computed the duties and taxes based on the declared value, but when the shipment is below Php 10,000 this is a deminimis value, it means exempted for duties and taxes but always remember that customs have the power to ask Consignee or shipper for any documents like proof of payment/purchase order to justify the correct value of shipment."