Hello, what I'll be sharing with you is what I know from P.D. 957 or also known as "THE SUBDIVISION AND CONDOMINIUM BUYERS' PROTECTIVE DECREE" and its implementing rules and regulation.
A developer who has a LICENSE TO SELL should have a completion date.
"Every owner or developer shall construct and provide the facilities, infrastructures, other forms of development, including water supply and lighting facilities and as far as practicable improvements, which are offered and indicated in the approved subdivision or condominium plans, brochures, prospectus, printed matters, letters or in any form of advertisement, within one ( 1) year or within such other period of time as may be fixed by the Board from the date of the issuance of license to sell for the subdivision or condominium project.
Request for extension of time to complete development of a subdivision or condominium project may be granted only in cases where non-completion of project is caused by fortuitous events, legal orders or such other reasons that the board may deem fit/proper with the written notice to lot or unit buyers without prejudice to the exercise of their rights pursuant to Section 23 of the Decree.
The request for extension of time for completion shall be accompanied by a revised work program duly signed and sealed by a licensed engineer or architect with project costing and financing schemes, therefore. In appropriate cases, the Board may require the posting of additional performance bond amounting to 20% of the development cost of the unfinished portion of the approved development plan, or issue such orders it may deem proper."
They should know since they are liable to HLURB. "Does not know" is not acceptable. You can't just keep on paying without knowing the completion date. Plus there is a loss on your part for the delayed years.
Anyway, a course of action you can do is if the developer can't really provide you the completion date after threatening them that you'll file a complaint with the HLURB, notify the developer via a formal letter that you'll stop making further payments. Get clearance from HLURB so you can back out on your purchase. Your total paid amount, excluding delinquency interests, but including amortization interests and legal interest rates should be reimbursed by the developer.
According to PD 957, "Section 23. Non-Forfeiture of Payments. No installment payment made by a buyer in a subdivision or condominium project for the lot or unit he contracted to buy shall be forfeited in favor of the owner or developer when the buyer, after due notice to the owner or developer, desists from further payment due to the failure of the owner or developer to develop the subdivision or condominium project according to the approved plans and within the time limit for complying with the same. Such buyer may, at his option, be reimbursed the total amount paid including amortization interests but excluding delinquency interests, with interest thereon at the legal rate."
Hope this helps. And if you want to learn more about real estate, you may want to check my Youtube channel, https://www.youtube.com/c/OwnPropertyPH.