One of the conditions reads; you must 'be physically present in Canada' before you can apply for your PR card. You can go to the Canada Immigration office site, and read this condition clearly.

Of course, there are lot of people cheating, just like the service company you mentioned. They collected all your documents, and send to their Canadian office. In their office, they invite a lawyer, who just sign your documents, stating that 'xxxx swear that all the information is true'. Of course, this is cheating again. After that, they will send the documents to the PR processing Centre in Nova Scotia. If everything is correct, you will receive a notice to collect the PR card. But if there is something wrong, and they need your additional information or identification card, say, driving license or whatever, then you are out of lunch.

To be honest is the best policy in Canada (probably not in China). Think it twice before you pay those cheaters. Good luck.