Old Fund Refusing To Cooperate As A Reference (Starting Competing Fund)

Hey monkeys, for reference I recently left a very reputable non-pod shop HF (think Pershing/Elliott/Glenview) as their Head of Macro as one of two individuals at the firm (the other being a C-Suiter) with trading authority. I have recently left to raise a competing fund and my old firm is trying to ruin my credibility by downplaying my involvement, role, title and alpha-generating abilities. They have downgraded my title from Head of Macro to Research Analyst when called for references, despite the fact that I have been referred to as Head of Macro in both internal and external (client presentations, industry conferences, etc) materials. 

How should I go about discreetly handling this situation so it won't damage my reputation especially while I'm talking to potential LPs for my new fund? I'm currently on very bad terms with select individuals at my old fund, so anything involving them isn't an option.