Surprise experience with Dell Pro support

I have an open case with Dell Pro Support for almost a month, the last phone call conversation is if I can't guarantee motherboard replacement can surely fix the issue, they refuse to send a tech to do motherboard replacement. we do I need to provide a solution to ensure the issue can be fixed?

I've spend lots time help to do troubleshooting and the latest phone call says he can't see me spend time on this and trying to teach me how to do my job.

Feels so funny for this specific case after using Dell Pro support for over 10 years...