As Andy has said, pull the bottom pulley off and take a look at the timing belt gear where it locates on the crankshaft. The crank has 2 flats that the pulley sits against.
The crankshafts are extremely soft and the pulley just rotates on the nose of the crank. (The crank sensor timing pulley is pinned to the belt pulley, so there's very rarely a DTC stored for timing)!

I've recently put a new crankshaft, oil pump and gear in an 05 plate under warranty with no service history.....

If crank is worn get them to contact Kia customer services.
Unless you wish to do it yourself of course.