Can my landlord in spain in our longterm rental change our locks we are in the Uk and have not been to the apartment since January 2020 and we agreed to pay the landlord reduced rent from April when the covid 19 thing started we have paid him 80 % for every month since and it was agreed when we can start traveling again we would pay him back full rent plus an extra 50 euros a month on top he now tells us he wants all the money now and has chainged the locks on the apartment and is keeping our stuff as well can he do this any advise please as we are in the uk and can't get there,