Falsification of Official Receipts for reimbursement

I submitted my reimbursement for the circumcision of my son. According to our medical benefits, Minor operation for outpatient can be reimbursed. When I was about to pay the cashier she issued me only a receipt for the Facility fee and the Professional fee in another receipt which is not registered with the BIR. I then asked her to add the Professional Fee in the OR which is allowed by our office. She put a ^caret sign for the amount in words for the Professional Fee. I prepared the voucher for said reimbursement of Professional Fee. I was then issued with an NTE to explain the OR with a caret sign, so I asked a certification on how much I paid for said circumcision and submit it together with my explanation. I am now scheduled for investigation. What are the other aspects that they can accused me regarding this case of mine? Is it right to accused me this falsification without any inquiry first from my end? Please help me!

Try to talk to the doctor's office to issue some kind of statement that such was indeed paid.

it is not falsification to put something in a document which is true