Repeat after me: All Landlords Are Bastards.
For want of a pressed metal lock that – if I could find one – costs less than 5 quid, they will withhold £100 of the bond. All Landlords Are Bastards. No way could we find one today, any hardware shops will be closed tomorrow (the large shops don’t do this lock) and tomorrow they want the house back. Until I hand the keys over, I am the tenant. Once I hand the keys over, anything I do will be criminal damage. I could cheerfully cause well over that amount of damage.
Update: J has agreed a trade with him. He gives us the money, we give him the keys. He’s not keen on the idea but who cares ? :)