Develop a Client Account platform

I already have a functioning website but I need someone to develop a User Account platform much like online banking account platform so clients can log into their account and check their status, make payments online, send messages, chat with a representative etc. Also I would like the person to develop a test for the current website. This will be a quick job therefore the budget is low as the main account is already set up and ideally I will like something to be done/finished by Sunday 19th October.