poor service

I have a contract phone with vodacom , i actually just had an upgrade. i must say that i am very disappointed in the customer service i have received thus far, when you call vodacom there agents are not very helpful and can hardly explain to you what extra charges you have on your account,i had a problem with my bill being higher every month i then found out that it was because of airtime advance i then cancelled it and asked them to remove it ,which was done, this month i have the same problem with my amount payable,i called the call centre and was help by someone who advised that they will escalate my problem, all i want is clear information and a clear understanding as to why vodacom is debiting a different amount every month a amount that i did not sign up for, i feel like i am getting ********** and being a very loyal customer its really disappointing ....i doubt i would recommend anybody to take out a contract with vodacom