Customer dissatisfaction

I received a call today from CellC informing me that i took out a new cellphone contract with them yesterday, When i inform them that i cannot recall myself doing that and they need to cancel everything now, they say i must write an affidavit, bring ,y bank statement and payslip to the nearest branch. When i tell them that i cant go through all the trouble for something that i didn't request, they say they cannot help me. As a loyal customer to Cell C i am very disappointed with their service.