If you feel that you cannot provide any other documents then you may either:
1. Offer to pay 7 months in advance or
2. Get an existing Globe subscriber of good standing who has enough credit stature to serve as your guarantor. As a guarantor, he would be equally liable for all liabilities you would incur in case you get approved.
To get iPhone 6 at 1799, you should have at least 2000 credit limit which is equivalent to 20K gross monthly income. to increase your credit limit, you should present additional proof of income. alternatively, check out ChitoReyes info.