Notwendigshop.de review for Google & YouTube

This app is terrible. It says everything is connected, but in reality conversions and audiences are not being tracked. I basically wasted €800 on Google Ads. I've been trying to figure out what to fix and where for two weeks now. I started digging deeper and found that in the app the correct Google Ads account is connected, but in the code it's actually a completely different one. At this point I have no idea what to do anymore. This is just awful!!!