INCORRECT BILLING - MTN KYALAMI CORNER MIDRAND

I signed 2 Additional contracts on my MTN Account with the Kyalami Corner Midrand Store. I requested the July 2018 promotional deal for Huawei Y3 2018 on MTN Made for Me M Package @ R169 x 24months. The lady who assisted me was Tsenolo. When I went to collect the phones their systems was offline, so I unfortunately did not receive a copy of the contract I signed. She advised me that she she was going to email me a copy, to date she has not done this. Now I received my Statement/Invoices and see that I am being billed incorrectly more than R169. I am a business person and do not have the time to go into to the store to resolve this incorrect billing query. Please rectify your mistake and ensure that before I receive my next invoice I am credited and put on the correct package and billed correctly going forward. You can contact me should you need any further information.