'Lost' annual rental money

I run a guesthouse and had 7 Telkom pay-as-you-go telephone lines which I had had for around 7/8 years. I paid an annual subscription of around R190 per phone line (renewal date varied per phone). As per usual we loaded the annual rental with phone vouchers at various dates in 2015. Telkom lost all record of 6 of these renewals (and the payments) and cut off the lines. All happened at the time when there was no operational call centre at Telkom (no telecommunication with a telecoms company!) so had to spend hours at the Rosebank Branch but they were not able to sort out the problem. So not only do they have no record of 6 X R190 worth of rental but we have no phone lines. And to add salt to the wound I get weekly Telkom sales people asking me to sign up for fibre optic with Telkom. Good customer service and reliability are key in any service industry but particularly so in the telecommunication industry. Very poor service with no way of solving the problem. Telkom if you want my business you need to sort this mess out.