Vodacom poor service

I took over my mother's affairs after my father past away end Aug. I've sent an email to complaints on 17 September because when I call I could only speak to a machine and it did not have an option to talk to a consultant and was definitely user friendly. When I google when I select send email it refers me back to the call centre. I requested them to send me information of all the contracts on my parents names. Reason is collections keep calling me (my mother referred them to me) for outstanding fees but both my parents had/have prepaid. My mother can't tell me anything about the contracts. After a lot of harassment I paid R4,200 into the account they sms through to me. Afterwards I still received calls for outstanding cost. I rep**** to my email again asking for them to advise the cell number for the payment I already made and the one they are calling me about. 2 ladies called me after numerous complaint email I've sent but not one of them could assist me. I've sent a few emails complaining and stating that I will not pay any outstanding amounts if they can not tell me for what number it is. I also want to know the payment I've made for what number that was. With regret I've paid that because of the harassment without them providing me with the information I requested.