I would contact Digitec's customer service directly. They can certainly order them for you.

Samsung Electronics GmbH
Hello,
You can enquire about the availability of the remote control you need for your Soundbar HW-T550/EN by calling 06196 9340 209 (Monday to Friday between 08:00 and 19:00; cost of the call according to the conditions of the contract partner for landline or mobile phone connections).
Best regards from Schwalbach,
Your Samsung Service Team