Address Error in App

Hello :) My first order from Sezane was meant to arrive today, which I have been highly anticipating for a week.. Unfortunately I received an email from dhl express that the package isn't able to be delivered due to my address being incorrect. So I checked the app and my address number was missing. I added it again and it gets deleted every single time. Even though I didn't know about this error, I had the entire address in the last column "Address name" in which I put my entire address and details that are needed for a successful delivery but I guess Sezane didn't put any of that on the package and also didn't realise the number was missing but obviously part of this last column. I sent a video of proof that the number is getting deteled in the app to Sezanes customer service and the answer that I received was to not use the App when ordering which seems... idk how to describe it. If I can't order using the App then the App is obsolete. This is all very annoying because I purposely added my entire address in this last collumn but they didn't refer to it at all. I don't understand why the App deletes the number in the "number column" but I feel like this should be fixed instead of telling me to order in the web browser.

Luckily, I ordered with dhl express because unlike normal dhl I could change the address there and I will get a new delivery date. With normal dhl the package would have just been send back which would have been extremely annoying.