Hi there. Didn't the e-mail that you've received from CIC has the instructions on how to proceed? If its less than a week, I wouldn't be too worried. Give it one more week and next Monday, send them an e-mail explaining the situation and requesting them for information on how to proceed.
You can also call CIC Call centre at 1888-242-2100 and speak to the agent on how to proceed.
Paying RPRF is pretty easy and I got instructions if you like them. I just paid mine upfront yesterday and send the scanned receipt to CIC today.. As for MR, you have to choose a CIC appointed panel physician and do your medicals there. If you are in Winnipeg, I can guide you on how to proceed but if you're elsewhere, you gotta call or e-mail CIC for further instructions. Hope it works out for you... Good luck..