MTN is overcharging me!!

It seems that I’ve been the victim of yet another billing error.

I have a contract for R1399 per month. In March I added the 200minute bundle for R119 per month. Therefore my monthly debit order should be R1518.

In May I was billed R1886.74 instead of R1756.00. In June I was billed R1669.00 instead of R1518.00. In July I was billed R1669.00 instead of R1518.00.

I've raised this with several "consultants" at MTN and even sent them my complaint on Twitter but no one seems to be doing anything about it and I'm sure I will be overcharged in August as well.