Translation:We do not buy tea in your stores.
As a native English speaker - it's somewhat awkward but depending on emphasis it is possible. For example if you're boycotting the stores then it would be "we don't buy tea in your stores." But you could say "In your stores, we don't buy tea. We buy other things there. We buy our tea in other stores." If that were what I wanted to say, is "Ve vašich obchodech čaj nekupujeme" an appropriate translation?