Bad service from AVIS

I don't advice anyone to hire Avis car yoh terrible treatment experience from Custormer care services which is Lawrence Marago and Nonzukiso.Lawrence just dropped the phone while I was explaining about overcharged amount as they failed to explain to e why I was charged that amount after I paid all the amount when I call several times he was not answering his phone.Both Lawrence and Nonzukiso they are not qualified to work at AVIS they ignored my email where I was requesting for clarity its been regarding the charges they just ignore the email....