Wes bank charges

I received an invoice from Wes bank for R 766.15 for trace/collection fee. my account was paid last month and an extra 66 % of my premium was paid extra in the account. I am paying late this month so 1/3 of my premium is in arrears. They have my home address / they have my email address and my sell no. I phoned call center and they said - will send you to thami and her direct no is ***. they drop my call. i phone the number - no one answers. Here is my question - can i now charge Wes bank R 766 for every call they do not answer. This action from Wes bank shows their attitude towards their client's while they can do what they pleased with and not be taxed for it. Choose your next financier very carefully. the extra funds i paid they, refused to take it off the account / they show a credit on your account. just so that they can charge you the full interest on your account. Choose very very carefully your next financier.