This was exactly my issue. My permit shows the wrong NOC. I provided CIC with my immigration papers that I presented at the border, which clearly said I arrived as a "tester" and applied for a permit as a "tester" then, of course. I also told the officer at the border once more what exactly I was doing. I have no clue why he gave me the wrong NOC in the end, but some officers are not very familiar with certain jobs, I suppose, no matter how well you explain them. My file had been re-opened. I am hoping for the best. I don't understand why honest people who arrive with the best intentions always end up in such situations.
A former colleague of mine also told me about a similar situation she was facing. The worked as a tester and the CBSA officer wrote Web Developer on her permit. She knew a lot about immigration rules and noticed it herself.