Overcharged

I got a statement on the 13th of march this year indicating that my amount due for end of March was R324, 50 but to my surprise an extra R150 was deducted for an online upgrade that I cancelled . I called vodacome sales and upgrades and the said accounts dept will assist with the refund , i got transferred to them and they said online department will help me not them. When i got to online dept they said they cant help me also. Im told i mst send an email to accounts dept but its the same dept that told me that they cant help me , only online dept can assist. Im getting tired of always getting *********** people when i call Vodacom for assistance.