First of all congrats, if your CC is charged, your PER is on its way, no doubt abt it...
It is most unlikely that they contact the Employer before issuing PER. Only the Visa office will check the employment details in detail. However, we had one case shared by a forumite where the supervisor of that member got a call from CIC 7 30 AM in the morning IST.
Yes, keep trying the call center and ask for UCI, but you wont see anything online before you get the PER.. Sometimes you hear that" they have received your application on (date) " in the IVR of CIC...