Moneyplant Research Indore - services was undelivered

I have paid ***** as half payment for * month advisory service to moneyplant research , their executives initally asked for pay in small amount as per convience. But they haress everyday to pay full amount of *****, so as to recieve services properly , where In they have not given any written document which says full amount needs to be paid prior to avail service .
their support staff and service staff both differs in their terms & conditions.
I want company should render proper service to me and I will pay the amount decided in intervals.