I just received the same type of call. The person said that they were with Revenue Canada and that I had committed fraud on my taxes and could spend up to 18 months in jail, and that I owed $4000 +
I asked how I could pay this amount, and first they wanted to know IF I had the amount. I told them I wasn't sure... he said he couldn't tell me how I could pay the amount unless I confirmed I had the funds. Then I told him I found this number on a website and it said was a scam, and he said that I had wasted his time, and he was going hang up and I would learn soon it wasn't a scam. Freaky! He talked about lawyers and court and all sorts of crazy stuff.