Try to understand the additional charges on my bill.

Hi PJP352 or Jianping.,

I took a look at your current bill. You sent 4 MMS to one number on 14, 15 & 18.3. If an SMS contains something other than text characters (e.g. pictures), the message is automatically converted into an MMS.
SMS are included in your tariff, that is correct. MMS, on the other hand, are subject to a charge and cost at least € 0.39 each, depending on the size.

In the previous bill, a message was sent to a special number. However, as only the abbreviated number is displayed, I cannot tell you to which service this message was sent.

I have moved your post to the correct section of the forum

Greetings Steffi