Hi Trev, best of luck with your site owner. The Mobile Home Act does now require site owners to recognise QRAs'. You need to write to your site owner to explain that you believe you are a QRA within the meaning of the legislation and request that the site owner recognises it as such within 28 days.
If the site owner fails to do so, the QRA can make an application to the Residential Property Tribunal www.justice.gov.uk for recognition, I think it cost £150 though!. If the tribunal grants this, the site owner is then obliged to recognise your QRA.
I am no legal expert but was in a similar situation to you and sought expert legal advice which did resolve things; it is always better to try to open a dialogue rather than resort to solisitors, sadly some poeple are just not reasonable. Best wishes.