The obligation to pay a worker on time is so central to Jewish ethics that failure to do is a violation of five Biblical commandments (eating pork in contrast, violates just one). While in today's environment, with paper trails and backups, disputes over whether a worker was actually paid are almost unheard of, such was not the case during Talmudic times.
In recognition of the fact that employers are less inclined to remember the details of each and every employee, whereas the worker surely will know if he was paid, in a dispute over unpaid wages it is the employee who is given the opportunity to take an oath of non-payment enabling him to then receive his wages. This is a reversal of normal judicial jurisprudence which states that it is the defendant i.e. employer, who would normally take an oath in order to absolve himself of any monies owing.
However an employee claiming back wages is quite limited in his time for a claim. If he tarries he forfeits the right to swear an oath that he was not paid. In general when it comes to monetary law Judaism has a very short statue of limitations. To do otherwise would be to create economic uncertainty - the enemy of a smooth running marketplace - with parties never sure there transactions are fully binding. Thus if one is overcharged for an object the Talmud expects that one would enter a claim that very same day - and if none is entered one forever losses the legal right to compensation despite the moral wrong perpetrated against them.
Interestingly when it comes to criminal activity or even ritual law Judaism recognizes no statue of limitations - the need for atonement never lapses. Thus if one has stolen money from another, that debt is never forgiven or forgotten until re-paid. In fact Jewish law even discusses under which situations and heir is obligated to repay monies owed by their parents.
CIBC is currently facing a lawsuit, potentially totalling 600 million dollars, alleging the bank does not pay its tellers and some other front-line workers for overtime. Such a suit would seem to have little merit in a Jewish court. In bringing fort the claims for back wages a CIBC teller claims she has for the last nine years been forced to work overtime of between two and five hours a week, work for which she was not paid above her regular wages.
Even if we were to assume that her claim was to be accepted at face value and the extra work demanded of her was improper, the time has long past to make such a claim. By continuing her overtime for close to ten years she forfeits her rights to lodge a complaint. The time to speak up is immediately when a wrong is perpetrated.
Furthermore it is far from certain her claim - even accepting her version of events - has much validity even if filed on time. Unpaid overtime is part and parcel of today's working environment. While from a secular legal perspective this is only true for professionals and management and not for non -management employees such as a bank teller, Jewish law accepts the binding nature of local custom. Actual practice overrides "official" titles. If it is common place and part of the workplace culture for employees to have to work extra such work becomes part of the regular job. While an employer may not mislead a potential employee regarding any work conditions the employee to bears some responsibility to investigate the "unwritten" rules of the workplace. Of course as citizens of Canada it is Canadian law and not Jewish law which is to be followed in monetary law.