The list of my individual connections and total min./MB are below my included service limit, but I still have to pay. Why?
Every itemized individual connection is rounded up, based on the type of subscription. Mobile Internet is billed in 20 KB increments, meaning that every connection is rounded up to the nearest 20 KB before it is subtracted from the included volume. Some subscriptions are billed on a per minute basis (every phone call is rounded up to the nearest minute), while other subscriptions are billed to the second. You will find your subscription's time frequency in the contract details.
Roaming is always billed by the minute. So every connection made abroad is rounded up to the nearest minute and then subtracted from the included volume.