Ground rent notice not received by 18 lease holders?

Long story short, we had a new landlord who was late sending the march ground rent out and 18 leaseholders did not receive it. We did not know who the new landlord was or any payment details.

We made a joint complaint to PDC (property debt collection) who very quickly got involved and even asked our local MP. A year on all but me were forced into paying £925 to stop their credit score from being affected and to end the bullying.

I have now found that this is a scam in order for PDC to produce and print cash.https://thepropertyagentscam.wordpress.com/2020/11/06/the-service-charge-debt-collection-scam/

I will not be bullied into paying this with all the evidence I had supplied and a financial disclosure.

How do I get them off my back? I never refused to pay it but the landlord refused to discuss the matter and told me to talk to PDC direct. I have submitted a financial disclosure and a lot of evidence, which they disregarded and now what to force me to sell my flat to pay this debt.

Many thanks

Nina