ABN AMRO Credit Card — monthly statement

hi after my transaction its been 3 months initially they not started sending me the statement then in fear i have deposited the first month bill in drop box with that after five months abn amro telling check is not in correct ways signed and by that time started charging interest witha all my complaints number they are telling its not correct refrence number . i am asking for a settelement but bank is chaging me the additional interest which i am not liable to pay even so many times they calling and giving me some bad remarks in phone by the agaents and even i will cal them they will say we will keep on charging interest!

please advice