Trash service and no answer

Hi. I've been making use os your extra time services, I recharged my account about a week ago and recieved a text that confirms my balance as a R0.00 however when I checked using th USSD Code it said I still owed R30.00 I write to you and tried to call your contact center and no response on both angles.

Again I made use of the extra time service, I checked using the ussd code before recharging and it said I owed R116.00. I made a recharge of R130.00 and my XtraTime balance still reflects that I owe you R30.00. My current airtime balance is at around R40.00. Why aren't you fully collecting your funds if I owe you. Please explain to me how or why I still find myself owing you R30.00 that can not be explained while I Continously recieve texts confirming the balance as R0.0 0