Dear SA - to reply or not, and if you do reply what do you say?

If I replied, and I am not sure whether i would or not, then I would say 'I have no idea who is making the calls. Why not raise it directly with the chlldre?'.

But the bigger question is the degree to which you are still financially entwined. If your xh assumed paying the bill, then the alleged misuse is clearly his problem, not yours. But if it is just 'unfinished business' then I would suggest you get things disentangled asap. Just so it is clear.