Slack service / response follow through

Staff were friendly at first - but then added something to the invoice which was exorbitant and something that was a hire NOT purchase item, meaning it would have been returned a few days later and they could not justify the cost. In fact when I questioned them twice to do so neither their staff members Lisa (who was polite as well but not very forthcoming with information - felt a bit like trying to draw blood from a stone, but that''s not uncommon in our country) or Normally, even bothered to get back to me. Not very good. And ended up being a massive waste of my time. Mildly annoyed.