Question for Philpost - Concepcion Post Office

My child transferred school from Las Pinas to Concepcion Tarlac, and upon transfer the school told us the they are just going to send thru registered mail the FORM 137 but its been a month, the school did not received yet??? then I ask my mother to get another copy and send it to me in my home adress in concepcion tarlac, but another 3 weeks had passed and I was not able to get this mail... where is it now?? where are the mails sent to me??