overcharge on accounts

Good day<br> <br> I took out two contracts with nashua mobile, which has now been taken over by Altech Autopage,<br> <br> Contracts signed with nashua are for R379.00 a month on both contracts, so far you have charged me the following:<br> <br> Account 1<br> <br> 19/12/14 R 389.00 (R 10.00 overcharge)<br> 15/01/15 R 419.19 (R 40.19 overcharge)<br> 16/02/15 R 400.24 (R 21.24 overcharge)<br> Total overcharge R 71.43<br> <br> Account 2<br> <br> 19/12/14 R 389.00 (R 10.00 overcharge)<br> 15/01/15 R 379.41 (R 00.41 overcharge)<br> 16/02/15 R 373.27 (R 5.73 undercharge)<br> Total overcharge (R 4.68<br> <br> Await feedback and refund<br> <br> Regards<br> <br> Tried calling on the 17/02/15 - waited about 45 min with no response, sent above email on 17/02/15 no response till now, called 25/02/15 spoke to customer service was pushed around to accounts and back to customer service when i asked to speak to Manager, i was transferred to 6 different people before being put on hold for about 10 min with no answer. I had no problem while with Nashua as soon as i was taken over by Altech - now i am being overcharged.