Vodacom billing

I recently contacted hellopeter with a billing problem with Vodacom and requested Vodacom to cancel my contract. I was contacted by someone from Vodacom and was told if I want the contract cancelled I must pay R5692.50 for a premature cancellation. This contract is only 2 months old. The initial contract was with Mondo mobile . R149. For 10gb of data day and 10gb of data night. Vodacom Is billing me R162. I desperately need hellopeters help