Senior Fare on Presto

Visited my sister in TO last week. I purchased a virtual Presto card for my Google wallet and preloaded it with $20 before I got there. My first use was to take the UP train -- at the airport I paid for a ride to downtown, and only then asked the agent on the platform about a senior fare (I'm 65). He told me to find customer service at Union Station and they could do it, but I couldn't get a refund for what I already paid. His colleague however, had me refund my fare at the machine, then worked some magic on her phone, held it up to mine and presto (sorry), my card was now a senior card. Three questions: (i) was she just doing me a favour and the guy was right? (ii) is there a way to buy a 'senior' card before getting to Toronto? and (iii) will my 'senior status' stick to the card I still have loaded? TIA.