Keyboard's keys are not working right

[l1nken]

So I bought a keyboard from a chinese web site aliexpress, huge mistake, I know... Name - Worlde Blue Whale 37. The problem is that 5 keys are working but not how they're supposed to. The most problematic is D# on the first octave: whenever I press it and hold it, instead of just sustaining a note it plays itself many many times per second, even though I never released it once. Other 4 work better, but not without issues: whenever I press and hold the key on very low velocity level it doesn't sustain at all, as if I instantly release it. Those 5 keys are - D# first octave, B first octave, G second octave, D# third octave, B third octave.
Here's a video of how it sounds (At that moment I only found out about 2 keys) -

I opened it up and tried to clean the contacts with 90% alcohol but not only it didn't help, the B on the first octave started to have the same problem as the D# on the first octave, instead of just not sustaining at low velocities.

 

[b3maniac]

I suggest that you contact the seller if it has a warranty. By mfg description, this is a portable midi controller rather than a musical instrument keyboard. If you are out of warranty, you should take it to a repair technician, or replace it with a working model. Good luck, Don

 

[Biggles]

Worlde Blue Whale 37 is £128 on Amazon so more expensive than M Audio and Akai models.

I would return it if possible and buy one from a recognised manufacturer