Writing a sarcastic letter to a solicitor - Germany

I just received a very lovely and funny letter from the solicitor representing my ex-employers. It contains a few lies, which I can back up and contradict with evidence that I have. Plus they magically calculated lost profit for the month of December even though the letter was sent middle of December. Funny guys. Anyway, I want to write an idiom or proverb in German about making lies, as I'd love to display a more poetic and philosophical side of me. Any suggestions and anyone know any?

Wasn't there an album called Talking to the Taxman about poetry?

No idea actually. I found a proverb in English, which I was wondering if there's a German equal. It goes: "He that will lie, will steal." To be honest, I've never heard it before, but it eloquently gives the one-finger salute, so I may just use it.

lies, lies and more lies

Here are a few

Lügen haben kurze Beine

Ehrlich währt am längsten

Wer einmal lügt, dem glaubt man nicht, selbst wenn er mal die Wahrheit spricht.

I'd be really careful, though, of directly accusing someone of lying. That could bring you even more trouble, I'd think. Something like "Folgende Äußerungen entsprechen nicht die Wahrheit" might be better.

What about 'lies will soon catch you out/up'. The nearest in German is 'Lügen haben kurze Beine.' Or regarding the fictitional profit-

give him an inch and he will take a mile is
Gib ihm den kleinen Finger und er nimmt die ganze Hand.

Thanks, the lie was about my ex-employer's claiming that I was not at work on my last day. But in fact, I had 2 meetings with 2 different managers at my client's office on this last day, as well as been sat at my desk working on my handover document. That's why I accuse them as lying, because it simply is utter bullshit what they conveyed to their solicitor.

Getretener Quark wird breit, nicht stark.*
The solicitor is stomping a topic to death but not proving anything.

*Yes, my boss once used this in a court document.

I like it and could be applied to *** ***'s lawyer. Sarabyrd, do you know much about the whole procedure for a company claiming for lost profit?

Just that they have to prove that you are to blame 100%. Ask a real lawyer and give your opponent hell from the start.

Forget about sending insults or witticisms. They won't help you and can sometimes even harm your position. They are asserting that you are un-business-like, aren't they? So why give them documentary ammunition?

This is business. You need to refute their assertions in a considered and cold-blooded manner. As Sara says, this sort of letter is best drafted by a professional. So find a lawyer, and keep your cool.

I agree so my letter does not contain any flippant remarks. It's slightly sarcastic in places, but so is their letter. I also finished off my letter by blatantly accusing them of lying about something they claimed in their letter (it's soooo easy for me to prove it too), so finishing it off with this seems justified.