Refusing to pay back incorrect payment made to them

We incorrectly paid one of our staff members wages into Cell C's FNB account on 8th Sept. The bank wants to charge us almost R300 PER ATTEMPT!! at reversing the transaction so I decided to rather approach Cell C directly to resolve the matter, as this is clearly day light ******* on the banks side! I called Cell C on the 12 Sept, was informed that it CAN be reversed and all I needed to do was to send an email explaining what happened to customer service with proof of payment and it would be sorted out within a week, I sent the email on the 12th Sept, the 18th Sept and a once again today (26th Sept) I also called today, to find out why I have had zero response to any of my emails and was now told by another person that they cannot help me because it wasn't paid in for a cellphone account, I must approach the bank to get it reversed. So which is it guy's? The lady I spoke to on the 12 Sept (Lindiwe, who got her information from her supervisor) was very helpful and the service was great, it went seriously downhill from there.... I do not even have the name of the female supervisor I just spoke to! To sum it up Cell C has received a payment not meant for them! One which they now refuse to pay back after informing me two weeks ago that they COULD and it would not be a problem, so my conclusion is that some seem quiet happy to work along with the banks to ***** the rest of us out of money. Nice guy's! Just a note Cell C: If the bank charges so much money PER ATTEMPT! at reversing a payment I would end up having to pay more money to the bank instead of getting money back as this is my 3rd attempt at getting Cell C just to respond to my request! Seriously unimpressed especially since I have just gotten a completely different information from the last time I called and the fact that they didn't even bother to respond to my emails