IMPORTANT! Please help. Has to do with GST cheques! :(?

Hello, im 18 years old, i had moved out of my mothers house almost a year ago due to certain reasons. My mother has been cashing my GST cheques into her account (signing them in her name) . I was wondering if there is ANY way i can stop this? i do not have direct deposit, BUT i just had done my taxes 1 week ago and handed them in exactly 7 days ago. I did sign for direct deposit for my gst cheques now on. I know they had sent out gst within the last couple of days to people, i was wondering if they would have changed my information to direct deposit yet or no. And if theres any way i could contact them to see if i can get my money back. I live in CANADA (ontario) thank you so much!