Like the others have said, for the price you paid you should expect a flawless job.
3K is pretty steep to start with and you certainly already paid a premium over what normally would be expected (1600-2000$ would be a usual ballpark)
I'd think you should go back to the installer and ask them why they used different films and have visible seams. Maybe even show them pictures from other cars which have Xpel/Suntec film on them and show no visible seams.
Hopefully they'll agree and redo their work with one kind of film and without seams.