New back door

Beware these doors are cheaper for a reason.
I ordered a new back door for my property and there were some initial mix up with delivery and this was delayed by a couple of weeks luckily this didn’t impact on installation as I had ordered early and was able to store once it arrived.
Once installed by a qualified joiner who has over 35 years in the trade I noticed that the door was sticking on opening and closing, my joiner returned and we then discovered that the fixing that screw into the frame (all pre installed by Just doors) had screws with no or minimal thread on then ( poor quality control) but also that the screws simply screw into the plastic of the frame and not into a specific area or metal plate that has been placed in the frame for that purpose (these doors although plastic are heavy).
I contacted Just doors who said this is how all there doors are made and no one else had raised an issues ( which I find very hard to believe my joiner though it was joke to be honest). All Just doors were prepared to do was send out slightly longer screw’s which had no effect and replace the screw with little or no thread I now have a door that is not usable.
Would avoid like the plague.