The Promise controller used in the 9860 has the capability of running either PATA or SATA. Which one you got depends on which hard drive you ordered (Sager built the 9860 with both types).
As I see it, you have two options. If you really did order your 9860 configured with an SATA drive, then your reseller screwed up and you can demand that they take it back and replace your PATA drive with an SATA one. If you actually ordered a PATA drive, you could ask them (or Sager) to send you a different (SATA) cable which you could use instead of the PATA cable you have installed now (might cost a few dollars). Then buy a $20 external USB 2.0 drive enclosure and use the PATA drive you have now externally. Or you might be able to find an external enclosure now for SATA drives if you'd rather go that route.