Permanent caveat next steps

[Guest]

I am disputing my father’s Will and have a permanent caveat.
Too much detail for the forum but executor is not willing to engage with mediation despite several requests. Also, executors solicitor has sent invoices to me for the storage of the deceased household effects.......storage charges worth more than household effects. It appears the invoices may not be real invoices!!
my questions: should the executor accept mediation to reduce the possibility of going to court?
what if it is found that the invoices are fraudulently created......can I request the executor be removed?