Why are the traffic query results different when sending text messages 108 and 702 to 10001?

The number 108 indicates how many MB was used and how long the Internet lasted, and the number 702 indicates how many MB are left. I posted both. Why are the results different?

For example, if I send a 108 check, I calculated the result and found that the check result was about half more than the 702 check result. When I went to the business office to check, the result was the same as the 702 check result. Which one do I believe? If I believe that the result of 702 uses up all the traffic of the package, then the result of 108 will be half as much. Will the excess be counted?