Mcdonald's Maitland

On 2 occasions within a period of 2 days I ordered at McDonald's Maitland branch. I used vouchers on the McDonald's app to which a free upside given but instead the staff wants to charge the free upsize price. On the first ocaassion the staff was arguing with me on the 24th Sep was under the influence and on the 2nd occasion the staff was not attentive as they didn't not want me to proceed with advising them of the situation. I am extremely disappointed by the service I received at McDonald's Maitland. In tr appalling manner which management handled the situation.