Did your portal status ever change to show everything submitted? If so, did you save a screenshot?
You say you mailed in transcript, school profile, etc with receipt. Typically that is sent from the school. Are you sure it was sent? I had them provide it in sealed signed envelopes and then I mailed it so I had control and was not stuck in the middle of the HS and the Academy.
When you called and spoke to someone telling you they had everything, do you know the name of the person you spoke to? Sometimes there are candidates with similar names, so they may have made a mistake.
If not, they will find it and everything will be okay. But stay on top of it. Ultimately it is the candidate's responsibility to ensure everything is received by the deadline.
Sorry you are having this stress. Let us know how it turns out.