How to increase Twitter DM API limit for per day



Twitter DM API limit is 1000 per day( )

But there is a company(bank) which has support from twitter and that company’s support account can send more than 50 000 DM per day.What is the algorithm behind this? How can I increase the DM API limit?The big company support account how handle and manage because they send more than 1000 DM per day