Misleading, unwilling to credit items

Our stores department was contacted and we agreed to the test op their product, we were not satisfied. but still they pushed items on us, we paid for product, and now they keep sending products and demanding payment.<br> We have paid for first delivery and want to send the other one back, they are telling us we are not allowed to do that because of some bulk agreement.<br> <br> Just goes to show - do not ever buy anything over the phone