Not sure if I've been conned or what rights I have

I've been having problems with Post Office broadband for a while, where pages take ages to load which is very annoying, and spoke to a couple of people but what they suggest didn't make any difference and then when I email them it's as if they just have actors pretending to be technical support who don't do anything.
My contract finished ages ago so I'm free to go to another company. Then on 6th September I had a phone call from Post Office about another 18 month contact, so I said that the service isn't much good so I don't want another contract. He was saying that he could save me money, but the 18 a month didn't seem much cheaper than I was having at the moment and my package didn't have calls included so the bill was quite expensive with calls added. He said I could have all calls included for free for three months, but he wasn't going to pressure me as I could have time to think about it.
I waited a while for information in the post so I could read and decide if I want it, but information in the post didn't give that much information, so I emailed to request somebody call me to go over the contract again, and it was a similar kind of person who helps with the technical work that doesn't know anything and can't help. All she said was it looks as if I took out the contract on 6th of September and I would have cancellation charges if I change now. So I said it looks as if I've been conned into taking out a contact then, and all she said was could she phone me back on Monday with her manager listening. I don't want to talk to her again as she doesn't know anything, and they're going to con me by saying I can't cancel the contact now.
Does anybody know who the ombudsman is or any organisation who can help me to know my rights?

To go to Ombudsman means you have to first exhaust the firms own complaints procedure and if deadlock arises you need to wait 8 to 10 weeks.

Did you agree at any time to the new contract?

Sounds like you may possibly have, and was planning to review the paperwork which never arrived.

In terms of time for pages to load, post a link to the results from a speed test at https://www.thinkbroadband.com/speedtest since if pages are slow to load, it may be that the line is slow, or there is a long delay in starting the page loads, both would shown up in the test.

Beyond the speed issue, it may be worth getting some advice from Citizens Advice around the general issue of contracts and distance selling.

It looks like you may of accidentally agreed to the new contact without you realising it.

That said, if you can show that the speed/service is not what they've promised you then you can cancel the contract without penalty as they are the ones that are breaking the contract and not you.

If they do try and say you have agreed to a contract tell them you want the recording of the call.

Pre-empt any hassle by making a Subject Access Request now for *all* details they hold about you. This will include recordings of calls, and won't cost you anything. They have a maximum of one calendar month to provide the information. Diarise the date.

If they are daft enough not to comply in that time then you need to open a complaint with the ICO (who are next to useless) and have the authority to order the company to comply, audit and slap them with a fine (but they won't). Best to make the request in writing (ie email). You don't need to fuss finding a data protection email address, but it might save a day or two. Organisations are required to provide role-specific training to all staff, recognising a SAR is something every member of staff needs to be able to do post-GDPR (one of the assertions made by the ICO in their nationwide roadshows) and records of such annual training is a key point the ICO stated they will review when complaints lead to an audit.

You can/should try to resolve your contract dispute in parallel.