Invalid electricity voucher

I bought electricity ar Boxer in Dobsonville when I get home the voucher is invalid, I couldn't redeem it went back a week later, they said they will call me to tell me what's wrong even today I have not received any call, I had to go to Shoprite to buy electricity. I was refunded or given a different voucher for electricity.

This not the first time the Boxer in Jeep street in JHB CBD I experienced a bad customer service and I reported it, however it was never taken into consideration or even get an apology call, I guess this company does not take it's customers seriously