After doing my own research, have decided to purchase an oyster card for my 2 full-day stay (18, 19 June)in London. My questions are:-
1. I'll arrive Heathrow (T3) at around 0630 Hr, is the ticketing office for the oyster card open?
2. On 20 June, I will leave at around 0735 Hr, is the refund counter for the oyster card at the Victoria Station open already?
3. Could I get a refund at the Victoria Station?
Many thanks for your help!