If you both announce a /24, the BGP route selection process should begin to
return some of the traffic to these prefixes back to your AS.
Also, if you begin to advertise your prefixes as /24s and as a result, they
try to advertise /25s, I would venture a guess that their /25s would
get blocked entirely, effectively returning traffic to those prefixes to
you. that would be best-case scenario until you can get someone at
AS36111 to listen to you.
Best of Luck to you