This has worked for me in the past, especially for settling debts.
I adopted a mantra of "remain professional", avoiding engaging with their emotional tantrum and escalating the situation, just sticking to the facts and explaining the situation to them and what needs to happen to reach a resolution.
It's hard, because people get emotional, and you have to force yourself to detach from them attacking the thing you have built and want to defend and instead become very objective, robotic in nature, but it works.
It's not for the light hearted but sometimes this is what it takes to get paid.
I adopted a mantra of "remain professional", avoiding engaging with their emotional tantrum and escalating the situation, just sticking to the facts and explaining the situation to them and what needs to happen to reach a resolution.
It's hard, because people get emotional, and you have to force yourself to detach from them attacking the thing you have built and want to defend and instead become very objective, robotic in nature, but it works.
It's not for the light hearted but sometimes this is what it takes to get paid.