As far as can be understood from the post, the flight was not cancelled. For some reason the OTA had cancelled the ticket. This has nothing to do with SK nor is denied boarding. Without tickets the OP and family were not able to travel. The OP needs to clear this with Travellink (as to why the tickets were cancelled; could it be that tickets were never issued?)

Clearly there is more to this story. Why would the OP contact the OTA ahead of traveling to make sure that "nobody can touch this booking"?