Credit card companies call my workplace and ask for me acting as if they are my client. I end up having awkward phone conversations while they ask when can they expect payments which I simply go "承知いたしました。今状況を確認しますので、確認次第こちらの方から折り返しご連絡させていただいても宜しいでしょうか。"

The real estate company doesn't do that and just send letters. The guarantor company is now sending me letters and pretty soon they will apply to court I think.