Cancellation notice issue

I just got off the chat with support, my contract ends on the 15th of May and I wanted to put in a cancellation notice since I'm unhappy with the services (the constant disconnects), and I decided to use the chat to do it since virgin media phone support is dog sh*t and I didn't want to spend the usual 45min+ getting transferred from one department to another.
so the person on the chat says that I need to give exactly 30 days, and I look in the contract there is nothing that says it needs to be exactly 30 days, and I do a quick google search and the first result is from this forum which says the notice can be given up to 60 days https://community.virginmedia.com/t5/Managing-Your-Account-Cable/Can-I-give-notice-to-cancel-more-than-30-days-before-end-of/td-p/5333501 
and this person refused to accept it and tries to disconnect me a few days early, and I say I want to talk to a manager, conveniently they are not there but suddely when I say I will call in and raise a complaint, they put in my notice.

so are these people acting like they have no clue, actually stupid, or they are maliciously lying to customers?

Can the moderator/admin on the forum confirm if my account will be disconnect once my contract ends on the 15th of May? I still haven't recieved a confirmation email and I don't trust virgin media.

[MOD EDIT: Subject title changed for clarity]