The first thing you should do is to take a screenshot to show that everything has been sent and is in order on your end. If possible, try to include an undeniable time and date in the picture so that you have a clear time stamp.
As far as not receiving your confirmation email goes, only those in charge of the application can answer this. Try contacting them at this email address: firstname.lastname@example.org\
Just make sure that you gave the correct email address and that the email didn't end up in the spam folder or some other place in your email before contacting them.
Additionally, check out this link https://www.bir.gov.ph/index.php/contact-us.html to see if you can get into a contact with one of the regional offices instead.