Greedy Landlord

Any advise on this would be greatly appreciated.

Essentially what is happening here is the landlord called to the house about 6 months ago, routine thing no issue. Its a three bed house( and registered with RTB as three bed) let direct to me( I am RTB registered), and I have two housemates (Licensees) in to help with rent. I am there three years.

While she was over she made a comment that she wasn't happy with with the front room, (Its empty except housemates work from home equipment and some storage) We asked her what she meant but she didn't elaborate (she's quiet a ditsy woman, all over the place all the time, or so I thought) The following month when rent was due, she said she was putting someone else into front room, or we can pay the extra €500 rent ourselves. (33% increase just like that) which was absolutely not going to happen.

We let her know in writing via text, that we are happy to pay an increase in rent (Which was only going to be 86 euro as we are in a RPZ, or we would be happy for her to carry out a rent review) There was no way in hell we were paying such an illegal increase, especially when she hasn't put a cent back into the house, its falling apart as it is.

She so kindly replied and said 'No problem, I will be putting someone into the front room January 1st then' We again advised her, she can't do this, the house is registered as a 3 bed, and she cannot put the rent up by €500, and again told her we would welcome a rent review.

Christmas passed and no response. I lodged the rent on the 1st (and I hand deliver part of the rent (€300 euro) to her every month on her request, clearly she in not declaring it) Upon calling and delivering, she bluntly said she will be in touch with me about the review, I replied oh yes the rent review? and she said no the termination my son is moving in.

Its funny how the original increase was 300, then 500, then someone moving in, now her son moving in.

I think she realized we wont be bullied and is trying to worm her way out maybe, she's got over 10k from us in cash also which I assume isn't declared.

She will have to prove and sign a stat declaration her son is moving in, I am 100% certain he is not, she is just trying to get us to leave now.

We gave her a chance to do a rent review, she has not yet served us a notice of termination, do we file a dispute with the RTB now re the rent just to have some record of her trying to do this to us?

Not sure what I am asking here, maybe just some advise.

Thanks a mil