How to prove the bad smell and force the building maintenance to fix it

Hello,

Just need to clarify this.

We are facing a serious (really horrible) drainage smell from the kitchen (sometimes we are unable to cook food due to the horrible smell) but unfortunately we can't give proof, pic... etc. on this case.

The stinking smell is not consistent or regular but somedays morning or other days at night. The building maintenance clearly knows the issue but they are not able to do anything and management is not taking any action.

The owner's office wont allow tenant's to contact the owner.

Kindly advise and help.