Form showing "Form over quota" error

We are not able to register children for soccer, as the parents are receiving this message.  Can you please advise why this is?

Bronze subscriptions allow for up to 10 payment submissions per calendar month.  Your account has received 13 payment submissions so far this month.  Upgrading to Silver would allow for up to 100 payment submissions per calendar month.  More information on what each subscription level allows for can be found in our pricing page:

https://secure.jotform.com/pricing