Email about TEXT limits?

We received an email today saying we have used 90% of our texts for the billing cycle. I pulled some metrics and we have used 782 texts this month so far with 14 days left in our billing cycle. Last billing cycle we used 1,289 texts and did not hit any limits. Why do we suddenly have some limit much lower than last month? Anyone else receive a message like this with mysterious limits you've never hit before?