How do i escalate an issue with Dell

Laptop wont power up. Have gone through virtual support - they have diagnosed that it needs a new motherboard. A ticket has been raised that claims new parts have been ordered and an engineer was due to arrive last week. No one arrived. I've added requests on the ticket for an update. The requests keep on being deleted and replaced with - 'customer initiated phone contact.' Can someone give me some useful info on how to get an update?