wrong bill

I took out a contract at cape gate telkom.First i wanted a 1 gig data contract but decide to rather take the 2.5 gig contract.My bill last month was more than what i budget for.I went to telkom in jeffreys bay and the lady look on the system and show me that i am paying for a 1 gig and a 2.5 gig contract.The 1 gig contract have a 061 ..... number.I never in my live had a 061 number before.I am using my 073 number on the contract.So who gave me 2 contracts.I want answers and my money back