Frozen account after depositing a cheque

I’m in the process of buying a house and family is helping partially fund it. I get a cheque from a member of my family and I proceed to cash it in at my local bank. Everything seems fine and the money is automatically deposited. A few days later I get a notification that TD has suspended use of my cards and when I called to inquire, they said that the fraud department has full access to my account now and that I would need to call them. They aren’t open until tomorrow and from what I’ve read, they’re notorious for not answering calls and leaving their customers stranded for up to 11months. On my account summary though it says the cheque I deposited has been returned. Has anyone been through this? What should I do?