You can modify the copy of the cancellation confirmation page via custom JavaScript. This allows you to add some additional explanation or perhaps try to convince the customer not to cancel by providing additional instructions or support.
To change the standard text to something else, you can use the following snippet. Put this snippet in Custom Code > Body on the Settings > Self Service Center page.
<script>
const cancellationTextElement = document.querySelector("#cancellation_allowed_text")
if (cancellationTextElement) {
cancellationTextElement.innerHTML = '<p class="text-base">Are you considering to cancel? Please call 0800-123456 if we can help you answer any questions at this point.</p>'
}
</script>
And it will for example look like this: