Double Billed for wrong contract loaded

We upgraded a cell contract on 13 Aug 2017. Went into a branch, showed the sales consultant the specials catalogue and asked to be upgraded to Huawei eP10 Lite for R269 pm. Special was on front page. Came with 10 gb extra data for 3mnths and 100 min/pm/24mnths. Didn't receive the extra 10gb or 100min. We assumed, that it would kick in after the 1st of Sep. After we didn't get the 10gb and 100 mins. We phoned telkom, who got the sales consultant to call back only to be told that it's not what we discussed, even though we asked for the deal on the front page of the catalogue. Told us she'd get backoffice to change it. We have had no luck in speaking to somebody who can help. Spoke to 5 different people, they still asked us to call back. Call back only to go through the whole story again. Eventually the correct deal was loaded, without any communication from Telkom. We've paid R539 in Sept, which we understand is because of pro-rata, but now in Oct, they have billed us R613.55 for a R269 contract. Seems like we are getting billed for Telkom's mess up