The DPE should be able to issue another temporary certificate. Do you know who the DPE manager is? You need to contact that person and have them track down what's happening. There is no reason why you shouldn't have been able to take the Commercial checkride and have it go through IACRA, it updates instantly, as soon as you complete the checkride and get issued the certificate, IACRA and the FAA database shows you are the grade/rating that you just completed, so that already sounds a little fishy. Sometimes when they mess up the DPE has to submit a paper 8710 or something else requires it. That's most likely what has to be done, but this is what you need to track down.