Even though they might do it there, we can't do it here unfortunately.
I'm sorry we can't offer that service here even though they do it at the other store.
この場合、次のような言い方ができますよ。
ーEven though they might do it there, we can't do it here unfortunately.
「そこでやっているかもしれませんが、あいにくここではできません」
ーI'm sorry we can't offer that service here even though they do it at the other store.
「すみません、他の店ではやっていてもそのサービスはここでは提供していません」
ご参考まで！
カナダ 
