MTN SO NOT REALIBLE AND POOR SERVICE

I am so angry and frustrated because two months back I placed an order online for a samsung J6 cellphone and I did get the phone but it came with 2 sim cards,one for data and the other for airtime. This was not told to me I expected to receive one sim card with both airtime and data.The same day the phone was delivered I queried this and was told they can't give me one sim card with both data and airtime then I had to return the phone same time to the nearest mtn store. Well the phone is with them but they are still debiting my account for a phone I do not have. What kind of service is this??? I have called them more than three times already and have Work Order number and reference from them, so why are they making my life difficult. I don't see myself having any other cellphone contract because of this appolling services