As for the stimulus ... if you don't get either of them by 1/27 when the efiling season is supposed to open then you can apply for both of them on your 2020 return.
As for the delayed 2019 refund ... to "sue" the IRS requires you to employ a tax attorney but that should be the last resort.
Try calling to check the status of your refund at the IRS website.
https://www.irs.gov/refunds
800-829-1040
First choose your language.
Then 2
Then 1
Then 3
Then 2
When asked for SSN do nothing it will ask twice
Then 2
Then 4
You should then be transferred to an agent, but there is likely to be a long wait.
If they can't assist you can try the Tax Advocate in your state. most are working remotely and have a backlog.
https://www.irs.gov/advocate/local-taxpayer-advocate
