Discover Student Loan Complaint

Discover Student loan department,

Non-federal student loan Dealing with my lender or servicer Need information about my balance/terms California

Discover student loans has been consistently harassing me and my co-signer about payment on a loan that they have been unable to provide proof that they own. I have asked for the original promissory note multiple times and have never received it. I would like to discontinue paying this loan until I see proof that it is owned by Discover. They continue to harass my co-signer and I about payments.