First of all check that it is not an SMS & MMS value added service to which you have subscribed. If this is the case, you are billed for each SMS & MMS you receive according to the conditions you signed up for.
You should send the deactivation command as soon as possible.
Please note that some Orange customers subscribe to 'chat' services via SMS. Later they identify the SMS received as improper, unwanted messages. Unfortunately they are very often subscribed to a service without being aware of how it operates or its conditions.
If you are unsure and if you do not wish to pursue it, delete the SMS/MMS.
If you receive this kind of SMS/MMS repeatedly, it may be that you are included on a list which authorizes advertising via SMS & MMS (competitions, etc.) If you can identify the source of the message, contact the sender and have your details removed from their mailing list. Beware calling back 0900, 0901 or 0906 numbers as these are billed at a premium rate and the call could be expensive!
It is also possible that it is unsolicited advertising sent en masse to our customers by third parties (spam). If this is the case, unfortunately it is not always possible to take action because the messages may originate from abroad and it will therefore be difficult to stop them.