Blender Duronic

Damage to this device extremely hard and complicated to implement.
The screw and unscrew it is a complex matter, the dangerous limit.
Despite the joint well established; overflow and cause burns (pulse function)
Seller very nice and attentive; but despite its very attractive price, the unit does not follow.
In addition, when returning for refund, it is deducted the sum of 12 euros (for participation
in referral fees on labels to print yourself; This represents a loss of 1/4
the value of the unit)
I find it completely abnormal (it appears that it is stated in the conditions of return ????)
The partial refund is announced, I challenge to Amazon.
Personally, it is a failure.