Toilet Etiquette

I'm at home and need to know when the dry cleaners close because its almost 6.55pm and if they close at 7 then i need to run down asap.

So i call out a few times and ask.

No answer

He's in the toilet and as later explained heard the question but can't answer when in the toilet.

I knew guys can't do two things at once but thats just ridiculous.