Here's one I sent out to Bank of Ireland two weeks ago. (Names have been changed to protect the innocent and not so innocent)

©Joseph-Patrick: Bloggs Authorised Representative for
JOE BLOGGS™ and all derivatives thereof.
C/o 9 My Gaff
Quaint Little Village
Co. Kildare
I. Grabbim
Group Chief Executive,
The Banksters,
40 Mespil Road,
Dublin 4.
CC: I. Squeezim, Collections Department
7 March 2011
Re: Mortgage Account No. XXXXXX
Non-Negotiable
Notice of Irrevocable Estoppel by Acquiescence
Notice to Agent is Notice to Principal Notice to Principal is Notice to Agent
Dear I. Grabbim
With reference to the letters dated 14 January, 24 January and 3 February all delivered by registered mail.
In those letters I asked you to provide the following reasonably requested specific items:
1. Validation of the debt (the actual accounting);
2. Verification of your claim against me (a sworn affidavit or a hand signed invoice in accordance with Bills of Exchange Act (1882) );
3. A copy of the contract signed by both parties and therefore binding both parties.
I herby serve Notice that Bank of Ireland/ICS Building Society’s failure to provide Proof of Claim has created a permanent and irrevocable estoppel by acquiescence, forevermore barring Bank of Ireland/ICS Building Society from bringing any and all claims, legal actions, orders, demands, lawsuits, costs, levies, penalties, damages, interests, liens and expenses whatsoever, against JOE BLOGGS™.
It is important that you acknowledge and understand that this is not a letter but a legal notice, which is a different specie of correspondence all together. I hereby declare that the law of agent and principal shall apply and that service upon one is service upon another.
Furthermore, your failure to provide Proof of Claim in the form of the above reasonably requested specific items comprises the tacit procuration of Bank of Ireland/ICS Building Society’s agreement to the following terms and conditions.
1. That the debt did not exist in the first place;
OR
2. It has already been paid in full;
AND
3. That any damages I suffer, you will be held culpable;
4. That any negative remarks made to a credit reference agency will be removed;
5. You will no longer pursue this matter any further.
6. You agree to pay all fee schedules.
Fee Schedule
Any further invalid claims against JOE BLOGGS™ and/or attempting to contact the Authorised Representative by mail, mobile phone and/or telephone will constitute the agreement of Bank of Ireland/ICS Building Society to the following Fee Schedule:
1. €1000.00 (ONE THOUSAND EURO) per invalid claim in writing, nunc pro tunc,
2. €1000.00 (ONE THOUSAND EURO) per letter and/or notice sent by recorded mail,nunc pro tunc,
3. €1000.00 (ONE THOUSAND EURO) per hour or portion thereof, of the Authorised Representative’s time, nunc pro tunc,
4. €1000.00 (ONE THOUSAND EURO) per attempt to contact by telephone and/or mobile phone.
5. €1,000,000 (ONE MILLION EURO) per unauthorised © or ™ infringement.
All fees are payable in Twenty One (21) days of date of invoice is received, as evidenced by registered mail tracking number.
Without malice or mischief, in sincerity and honour
By:
By: ©Joseph-Patrick: Bloggs; Authorised Representative
Errors & Omissions Excepted
WITHOUT PREJUDICE – WITHOUT RECOURSE – NON-ASSUMPSIT