Billed for Item I did not sign up for

I app**** for the SmartBroadband Wireless 10GB + Huawei B593 in September and received it on the 23rd of September after I lodged a complaint on Hello peter due to non delivery. When I got to the Sandton shop to pick it up they noticed that they have given me the wrong deal R399 - 20GB where as I signed up for the R299 10GB deal. The said they will sort it out but what is strange is that I am now being billed for both devices/contracts which was R957.45, I phoned Telkom on the to inquire about this on the 27/10/2015 at about 09:19am and I spoke to Queen Masani who told me that my query will be resolved in 72 hours and they will give me a call - she gave me a reference number: ***1. This has never happened as I got another bill for both devices I then called Telkom again on the 03/11/2015 at about 11:02am and spoke to Thembisile Vilakazi who said her Team Leader said my query is not resolved yet but they will call me before the end of the day. I would like Telkom to cancel the mistake they made and refund my money I don't see why I should be paying for their incompetence!! I really am not impressed with their service and regret signing up with them!