Is it taking longer than 8 weeks to get your paper-filed personal tax return or T1 adjustment request assessed? Longer than 6 weeks to get your digital corporate tax return assessed?
Once you have tried to resolve this by talking to CRA agents (make sure you record their name and agent number) with no success, you have a right to file a service complaint with CRA. Their standard for resolving service complaints is 30 days. If you have no success by filing a service complaint, you can file a complaint with the Taxpayers' Ombudsman. You can read further details about the Taxpayer Bill of Rights here.