Nestaway Technologies — lazy nestaway employees

Myself owner of a flat who provided his flat to nestaway for rental purpose.
Its been 1 month tenant has vacated the flat, but nestaway has not handed over the keys to me, nor they have completed formalities like final settlement, house deep cleaning, performing repair works, utility bill payment etc.
Despite multiple folloups over email, none of above mentioned pending points have been actioned. Team member not even available over phone as if work from home in this pandemic situation for nestaway associates means only stay at home.
I would like to express my views on this platform & urge people not to handover property to nestaway.