Equifax refused to restore his credit score or explain why it dropped to zero, until Go Public started asking questions.

Only then did the company point to its little-known policy: If a credit file sits inactive, the consumer may be labelled "unscoreable" and their score reset to zero. Tregear says the last time he checked, before it disappeared, his score was around a more respectable 700.

Go Public has since found a major flaw in consumer protection rules — that there are no laws or oversight on how credit scores are calculated, leaving credit bureaus to do what they want.

Consumer advocate Geoff White says that gives credit bureaus too much power, with no transparency.