Problems with Dell service.

I've purchased a business laptop two years ago.
For the last three weeks i have hardware issues.
The dealer that I've purchased from (in Buchs AG) called Dell for service.(at the first time).
Although I've provided a video file showing that there is a multiple hardware issues, the technician replaced the monitor only.
Now, 2 weeks later, the same issue (one of the previous two) is back.
I've called Dell service for four times during yesterday.
Waited each time 30 minutes to be transferred to a private customers support. (Although a business / Firm paid for this computer and the model is for business model).
Each time after finally getting an answer, the call was conveniently disconnected.
I've never experience such a poor service.
Can anyone help ?
Ron Wagner