If your dad gets declined with a Plus loan, then your Stafford loan gets increased by about $4k each year. However, you're talking about private loans of $16k per year-about $65k for all 4 years PLUS your Stafford loans of about $30k. That's over $90k in loans.
This written warning is being issued pursuant to the guidelines of the University Disciplinary Policy, and will remain active in your personnel files for 12 months or until you receive at least an overall evaluation of Good and a Good on Principal Function 2 which covers your reporting responsibilities.
If possible, you should dispute the debt in writing within 30 days. If you send the letter within 30 days, the debt collector must stop trying to collect the debt until it can show you written proof of the debt or the name and address of the original creditor. (15 United States Code section 15 USC 1692g.)