The earliest copy I have on The Telegraph Rules, Regulations and Rates is from the 1924 Rosenstock's Manila Directory, selected sections reproduced for your valued information. 
The above rules from page 99 to 105, exclude  the actual telegraph rates except that telegrams are charged at 10 words minimum per zone rate (Section 20) and a 0.10 centavos additional fee charge on collect telegrams (Section 54).

Succeeding pages to 114 with a listing of municipalities, post offices, postal savings banks and telegraph offices by provinces.


Note: Reproduced pages re-formatted for this presentation.