Poochie Fashion review for Google & YouTube

Since having to update the old app to this version, Two months ago, I have had nothing but trouble. My sales are down 50-60%. Having contacted both Shopify and Google support several times over the last Two months, my shopping campaign has gone from bad to worse! Over half of my products were pending, however, support have re-synced the products twice and now there are only a few still "pending". Despite that, my sales, clicks, conversions and everything else have dropped. I increased my add spend, but strangely this has had no effect on my conversions/ sales. The new "Smart" campaign is terrible, with less features that the old campaigns. You get no useful support with either Shopify or Google on how to execute it correctly. My Original Google shopping app and campaign was doing really well, this app have almost ruined my business. I am at a loss as to what to do. Maybe the only option is to drop this app and go to a Paid app, and start all over again!