ABSA pre-paid electricity issue

I bought R300 prepaid electricity and got a "free" token with zero units on it. I tried again for R300 and got a token with 28 units. I don't have outstanding fees or anything with Eskom. I saw that R600 was deducted and logged a complaint with ABSA. Received several automated emails about it but was never contacted or refunded. R20 per unit is a bit much.