VASMARTT (VASMARTT TRUST ) DEBT COLLECTORS ?

I have received a call from this company called Vasmartt,and they say they are debt collectors and they calling on behalf of Multichoice .their contact number is ***,of which when I called back the number no one answers/answered and there is a funny disturbing noise that "some agents are currently busy" .The company is registered since 1996 on record and based in Western Cape , but has no website .They have sent me an sms saying I owe or rather should pay R116.50 and I don't know to pay it where , as they did not supply banking details...Multichoice has never contacted me or send me any communication that I owe them money , my account with Multi Choice is up to date ...so who exactly are these people,can you please help ...?