I would print out that the account balance is now zero, as well as print out a statement of your account showing you had the funds to make the payment in full. Ensure those documents are dated the same date. I would then print out some (or preferably all of the text messages). Your friend tried to unilaterally change the terms of the contract. I would have an attorney review the written contract and review the txts etc with you to further direct you, as that may very well dictate the legal advice that best serves you.
I would print out that the account balance is now zero, as well as print out a statement of your account showing you had the funds to make the payment in full. Ensure those documents are dated the same date. I would then print out some (or preferably all of the text messages). Your friend tried to unilaterally change the terms of the contract. I would have an attorney review the written contract and review the txts etc with you to further direct you, as that may very well dictate the legal advice that best serves you.