To get in touch with the company you invested in, you can reach out to their investor relations (IR) team. Typically, the email address for the IR team is available along the bottom banner of the DealMaker platform, and is contained in the emails you receive. Some IR teams may offer phone support, as well.
Further, please note there are databases you can search to obtain contact information:
If the company is a US public company, you can find their contact information here.
If they are a Canadian public company, you can find their contact information here.