Irregular Debit Orders

I called and approached by the Jabba Connect call center and offered a contract.. I initially advised them that I am interested as I was in another contract with another Service Provider. A Samsung J1 Cellular Handset was delivered to me. I attempted to cancel my contract with my current Service Provider but with no success. Jabba Connect was advised accordingly and requested them to collect the Handset rather as I could not afford and maintained two Cellular Contracts. I further requested them to also cancel the Debit Order Instruction and they agreed. I was further advised to pay an admin fee to the amount of R500-00 which I to date do not understand. I advised that I would return the Handset to them personally but instead I was advised that they will arrange with a courier to collect. The Handset was collected Three Weeks later. After I cancelled the contract with Jabba Connect two Debit Orders to the amount of R385.00 went through my personal bank account after I requested them to terminate my Debit Order Instruction with them. If I am liable for the R500-00 Admin Fee which I do not agree with, I would accept for the amount to be Debited against my Personal Bank Account