How to calculate broad band charges if migrate from one plan to another plan

[V A RAJU]

If I have taken broad band Unlimited combo 695 plan (in that plan 4mbps Upto 25 GB after that it reduces to 1 Mbps ) if I used 25 GB in 15 days after that I migrate to lower plan how they calculate. For 15 days 12.5 GB at the rate of 4mbps so they charge any extra for 12.5 GB

 

[dekaron123]

They dont calculate based on data, only on the cost of the plan

 

[geek]

pro rata basis