Vodacom deducts money despite cancelling contract

I entered a Vodacom contract through Elite Mobile. The arrangement was that if I send the phone back within the specified time, the contract will be null and void. I returned the phone within the specified time - and still Vodacom made three deductions from my account over 4 months amounting to over R400. Despite several calls to Elite Mobile and more calls to Vodacom, a visit to the Vodacom Customer Care Centre in Port Elizabeth and two emails I have not received any response on when I will be refunded.