A couple of years ago I bought a new Oxford Titan Disc Lock in UK. A week later I rode to Moscow, using it at stops on the way - fine.
Once I got here I went to a supermarket, put it on and went shopping. When I came out it would not unlock. Having insufficient cash left on me I had to walk 3 or 4 kilometers home.
I Emailed Oxford Customer Service asking what to do. It was about 8pm (5pm in UK) and I didnt fancy leaving my bike in a Moscow supermarket carpark overnight so I got a lift back with some tools. I unbolted the disc from the wheel and strapped it all (disc, lock, ABS ring, and brake hose) to the fork leg and managed to ride to our flat with only a rear brake.
Not the intended end to a long 3 day ride!
Next day Oxford replied with no suggestion other then go to a professsional locksmith!
After much hard work with an angle-grinder later, I eventually removed it.
Never again.
And that disc lock was less than two weeks old - what happens if they last long enough for the lock mechanism or key to wear a bit?
No doubt Oxford enjoyed my money

despite the inconvenience of answering my Email. I suppose they could have ignored it.