Advantage arms prob

So I got home from the FD this morning and waiting at home was my new conversion kit. I have a few hours this morning before heading to second job. I planned on putting on the conversion and heading to the range. Then the problems began.

I opened the kit checking condition and to make sure it's right model. All good careful read the directions and the attempted to put it on my lower. No go. For the life of me I can't get the glock lock into the locked position.

I've rechecked that it does fit my 23 gen 4. Reassembled per manufact directions still no go. By time their phone lines open on Cali it'll be 3 hrs from now and I've got to b at work. Any help?? Thx

 

Yep has 19/23 gen 4 stamped on the sude

 

So the firing pin travels freely and I can cock the pistol. Still can't get the slide lock to engage. Call advantage explained new upper won't lock onto my lower

So icallef them and after 20 min of trying to get a human, phone was answered by an extremely rude female. She asked if I had pressed muzzle into table top to get it to lock in. I assured her I have tried several times. She then replied "huh we test fire all of them. Send it to us and we will look at it. And the she promptly slammed the phone down before I could say anything.

So now I have to pay to ship their new defective product back!! ***??