Unfortunately, you will have to deal with them.
In my friend case, because she couldnt renew her sin number while waiting the pgwp paper, they cancelled her job offer.
(Because in their payroll system, it does not accept her expired sin number)
She contacted CRA and IRCC, but none of them took care her situation.
That's why there is a huge paradox what IRCC says that you can work while waiting for the decision,
but once their sin number expires, there is no way you can do it.
Human resources and small companies do not want to wait and they want solid evidence, which will highly cancel the offer.