I never have moment when their Trezor worked with their cable.
I always had to replace to a new Cable.
It has been working for me for few days and now the new cable not work as well.
Many connectivity problems
Connectivity issues either come from a faulty device (which is quite rare), a bad cable (most common) or missing drivers/rules (common mostly for some Linux users). If you've ever changed the cable with
a high-quality one and still have issues, it may be the Trezor device at fault. Remember that after many uses, cables may get faulty especially if you don't take proper care of the cable's endings.
I used to have problems with my Android <-> PC connection a long time ago. Ended up buying some very cheap Samsung cables only to later find out those
don't even connect to the PC at all and charging was extremely slow. Brand name =/= high quality.
If it's the device's fault, you should (I think) have a warranty for it). Contact the support as other members suggested above.
Why they don't make some tests before they launch millions trezors?
Are they stupid?
They always make tests beforehand, but it's almost impossible to launch a
perfect product. There are a lot of cars out there who've been found to have some serious issues in bulk. If you really don't like Trezor, then go for another HW brand such as Ledger. But don't expect perfection there either.