That is not entirely correct:
1.)
....with a customer service that cannot fix the problem in two months and with four visits/electricians
You have the option to withdraw from the purchase contract or request a new device. That is law, not goodwill.
But the refrigerator was usable, meaning it cools and is usable as such? Or did you have, besides loss of time and vacation, other things, that is, material damage (trips to IKEA, refrigerator not usable, therefore eating out, etc.)?
If the refrigerator was/is not usable, you have the option to claim damages. But everything must be proven (invoices/receipts/report to customer service).
2.)
....and the damage caused by customer service (€378 and a part that now has to be newly manufactured by the kitchen manufacturer) somewhat spoils the joy of the big kitchen project
Has the damage been reported to Bauknecht? Is it an obvious damage that could only have come from that?
If yes, was there any reaction from Bauknecht?
3.)
Since a refrigerator with that liter capacity and €699 is not exactly cheap,
With a 5-year warranty, that is already cheaper than many other devices, just as a side note.
4.)
in my opinion, the Whirlpool customer service neither has to uninstall the refrigerator nor install fronts.
Yes and no.
Installing and uninstalling fronts = No
The device is also delivered without attachments. But IKEA probably does this as goodwill upon request. On the other hand, it’s not that dramatic and can be done oneself with a bit of craftsmanship.
Uninstalling the device = Yes.
The device does not work properly, so the manufacturer is obliged to provide a functioning device. All work related to the device is at the manufacturer’s expense. The customer basically has the "all-inclusive package."
According to the law:
§ 437
Rights of the buyer in case of defects
If the item is defective, the buyer can, if the requirements of the following provisions are met and unless otherwise specified,
1. demand subsequent performance according to § 439,
2. withdraw from the contract according to §§ 440, 323 and 326 (5) or reduce the purchase price according to § 441, and
3. demand damages according to §§ 440, 280, 281, 283 and 311a or reimbursement of futile expenses according to § 284.
Source: dejure.org