Work permit application lost at CIC, help!

[FrustratedKaren]

July 2015 I sent in my application for an open work permit and my permanent residency in the same envelope to Vegreville. I paid the work permit application fee and included confirmation in the envelope. A year later, CIC is telling me they received the PR application but not my work permit application. Now I am being told I must stop working and start a new work permit application which could take 4 months to process. How it can be missing when it was in the same envelope I can't understand and they are taking no responsibility. Why would I pay the fee for the work permit online and then not send the application? What should I do now? I have tried my local MLA in Alberta and they can only repeat what CIC tells them. They ask for proof it was sent and I have my postage receipt, but how do you prove exactly what was inside the envelope unless you were standing there when they opened it? Any help greatly appreciated!