Please let me know, why the depart

Please let me know, why the depart schedule was changed ?
I need more information for explain to PDLT.
Yesterday, PDLT told me that they need to receive original documents in 15/10/13 before noon (local time) & they will finish customs clearance process and deliver to their plant rapidly.

ผลลัพธ์ (อังกฤษ) 3:

Please let me know, why the schedule was changed depart?
I need to explain PDLT for more information.
Yesterday, PDLT told me that they need to receive original documents in 10/15/13 before noon (local time), they will finish & customs clearance process and deliver to their plant rapidly.