Retrieving data from PHP form

I'm trying to send some data via phpMailer but I can get the input fields from the booking form.
I think it's because they've been formatted and I don't have any more ideas about how to do the job...

Basically I have the bform.php (form) filled up by the customer and on submit it's sent to the pre_booking-test.php file where the data is formatted and then sent to callback.php where 'raw' data's finally sent via phpMailer to the website admin. Someone has an idea how to 'parse' this raw data?
I'm attaching the files to make clear what is going on.
Cristian CarattiSoftware developerAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Cristian CarattiSoftware developerAuthor Commented:
Hi, Thank you for your suggestion.
I can get some data this way but in this format:
orderreference=QS54625+09jhtio76875d7bffa2d1ee1054491af6285+TT+Doc+Read+-+London+2018&paymenttype=INVOICE ($data)
is it possible to parse $data?
ex.   $data = file_get_contents('php://input');
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.