Who called from 2048189838

i been receiving calls from this number 1 204 818 9838, when i answer no one talks, and when i try to phone back the phone doesn't ring

I've received the same calls. No answer.

Says they're from Canadian Tire Mastercard... fraud prevention/monitoring program. For ALL of my other credit cards as well

I'm getting up to six calls a day from 204-818-9838. How can I stop them?

Consider getting a call blocking device or phone.. You can google them and many are around $40.00 or so. If its a cell phone, some already have call blocking, if not, there are free apps on the web that will work for some. You can google this. If you have a smart phone, there is a free app called call control. Iphones appear to have apps also. Another one is called Mr. Number.