2 complaints - London
I had the same telephone call - politely told them that my business partner was involved in property deals and I take all my soundings from him (he isn't, of course), but they politely went away.
Persistent and unsolicted phone call from Kensington Property Group claiming that I had contacted them previously (lie). Trying to sell property/land. Company appears to be shady: not known in the wider commercial property world and no/few 3rd party references on the web except from other people who have reported being similarly pestered. Unregulated business. Website has complete absence of any named people/staff/owners. Watch out!