To my knowledge, Sonos doesn’t add any advertisements to a stream (although perhaps in Sonos Radio?). If you’re getting ads from Deezer, they’re the ones inserting/providing the ad, and you may want to reach out to them. 

Full disclosure: I’m not a Deezer user.

Is this a free or paid account? The general rule for the services I’ve used is that “free” accounts will post ads from time to time — in an effort to support the service. I’ve noticed that some services might play for quite a while without ads, then they come rolling in — with increasing frequency. Perhaps this is an attempt to make me go away or start a pay account. For multi-site services, such as Audacity or TuneIn the service may insert an ad before transferring to the site. The site may then insert its own ads.

@buzz 

I'm not having a free account , I'm paying each month for not getting commercials.

What I really find weird is that it s only when listening to deezer through the Sonos. I don't have that on my mobile .... 

I don't understand . 

@Pampac 

For me it works absolutely fine with my deezer familly on Sonos. 
I just can imagine that you linked Sonos with a different account as you’re logged into deezer app on your smartphone. 
Is it the family plan master account you want to use with Sonos? Or is it a profile of this or a different account that was invited to family?

Please try do delete deezer from Sonos and reconnect it as a service using a correct account or profile. 

Unfortunately it didn't solve the issue... à week ago all was working fine . Paying for something that you are not supposed to have is abusive.... I'm just thinking going to another provider if it ...  

If your login data are correct, last try would be this:

Remove Deezer from Sonos, Log out from Deezer app on device with Sonos app, restart this device and all Sonos devices. Log in to Deezer account on a desktop webbrowser and select settings… my account… more… my apps. There remove Sonos from connected devices. 
Log in to Deezer app and connect Deezer to Sonos again. 
When you connect Deezer on Sonos, is there the question which family profile you like to add? Would be helpful, if you answer my questions from above what kind of account you connect to Sonos? Master family, profile or added account. 
If you prefer you can also get in contact with Deezer support team. 
https://support.deezer.com/hc/en-gb/requests/new