The proof, the register and the tracing are shown on screen before you pay, so you know what the exhibit will contain. If the exhibit you download does not match what the screen showed, or you could not download it, write to ville@docuritas.com within 14 days and the matter is refunded, no questions asked.
Separately: Every statement is proven against the bank's own printed figures before it becomes an exhibit, and one that cannot be proven says so on its face. If the engine does read a row wrong — as the engine read it, before any correction made in review — send that row's citation to ville@docuritas.com within 14 days and you are credited a further matter, run at no charge. That is a credit and not a payment back: the same files re-run with the corrected reading cost nothing in any case, inside the rerun window, and what you wanted was a correct exhibit. The credit covers rows read from a statement's text layer. Rows on pages read by OCR sit outside the credit — the register names those files, and section 11 of the exhibit states that a misread character on an OCR'd page is caught only where it breaks the arithmetic.
A matter is paid once and never renews, so there is nothing to cancel; the same matter re-runs at no charge inside the rerun window.