please help me dispute ,Vodacom

Went out of the country and come back and get a billing of R2065.00 1.My contract plan is not even that high 2.Vodacom claim that it was for Roaming but according to my knowledge i never activate this service (Please can you assist me by asking Vodacom who activated roaming on line ,I need a date ,Time and the person Also request a call record 3.I have give them my number to call they send sms saying they have been unable to reach me Reference are: ID *** CELL : *** Vodacom ref : *** and ***