Hey there, @fatald!
Unfortunately, I'm afraid you have exhausted all your DIY data recovery attempts and you might actually have made it harder for the data recovery services to retrieve the files.
Tampering with the HDD physically might have done even more damage, which would definitely be costly. The freezer trick is something that MIGHT work on a certain kind of hardware damage, but definitely, not in all cases of HDD corruption.
Your best bet would be a professional assistance.
I hope those guys help you! Keeping my fingers crossed for your data!
Best of luck!