VASMARTT TRUST CC

I received an sms from Vasmartt Trust CC stating they are authorised by Multichoice to collect an outstanding balance from me. The phone number in their sms does not work - it rings once then stops. If you click on the link they include in their message it opens up a payment page with options of payment methods. However I phoned Multichoice since I know my account is up to date and pay by debit order every month. Multichoice claims they do not know who this company is. Please beware.