I have deleted multiple older forms in our account, but it still tells me that we are out of space. Any suggestions?

Thank you for reporting us. 

When I checked your account and your usage details, you are in the limit of monthly submission.

Free user can get submission up to 100 as monthly. Once you reach this limit, your forms are disabled. Even you delete your submissions or forms, it does not decrease the monthly usage. You need to upgrade your account to a higher plan or wait until the beginning of the next month. Since, monthly usage limits reset 1st day of the each month. 

If you have more questions, please feel free to contact us again.