This is patently false. They will remove it if they are feeling particularly jolly when you call and ask. But they are under no obligation to do so and they have denied this action to me before.
I’ve been in this situation and you can make repayment contingent upon deleting the negative remarks. As in you send me a letter certifying you’ll delete the remark, and I will remit payment.
If they refuse then you can just refuse to pay until they relent. Their only alternative is to take you to court or sell to the next collection agency down the line. Creditors and collection agencies won’t take that action except as an absolute last resort.
One of the challenges with this is that technically the TOS between a creditor and the CRA forbids the practice of "pay for delete". So you may get lucky, but oftentimes, you may not.