Saving Attachment from Email Part using PHP - php

Question

I've come across a bit of a problem and was wondering if anyone could point me in the right direction, I'm writing a email parser that parses emails and extracts particular info.
It parses plain text emails(the emails are in a set format) using regex, this works fine.
If an email has an attachment which is of type 3 && encoding = 3 && disposition = attachment then save the attachment to local disk.
My problem is step 2:
I foreach through each email structure if it has more than 2 parts I attempt to decode the attachment and save it to disk, but this is failing.
If I try to simply use file_put_contents I get a 0 KB File, I have given full permissions to the wamp server user, So I do not think it's file permissions and I have verified I can write by using mkdir.
file_put_contents(APPPATH . "attachments/". $partofpart->dparameters[0]->value, $partofpart); //$partofpart is part[2] of the full email structure
So I attempted to decode the part and save the decoded part instead using file_put_contents
$attachment = base64_decode($partofpart);
var_dump($attachment);
//then save the attachment with attachment name
file_put_contents(APPPATH . "attachments/". $partofpart->dparameters[0]->value, $attachment);
but this returns an error saying base64_decode requires an string not an object, how do I then convert my email-part-attachment to a string for use by base64_decode?
Even just writing that out I feel I'm missing something obvious and shouldn't require the extra steps.
Am I right in thinking the part IS the attachment? All the parameters lead me to believe so, Type, Subtype, size etc are all correct for the attachment.
Link to the entire scraper model
Thanks for reading and any help.
Below is a vardump of parts that meet the type/encoding/disposition checks
I have worked out the problem, I was not fetching the actual pdf back just its structure
So I wrote a function to retrieve the body of the particular email then used imap_base64 to encode then finally file_put_contents.
function getAttachment($msg_index, $part)
{
$mailbody = imap_fetchbody($this->conn,$msg_index,$part);
return $mailbody;
}
$attachment = imap_base64($this->email_model->getAttachment($email['index'], "2"));
//mkdir(APPPATH . "attachmentzs/");
//then save the attachment with attachment name
file_put_contents(APPPATH . "attachments/". $partofpart->dparameters[0]->value, $attachment);