I believe they're handling the maintenance of ressies made under the old system, and ressied made under the new system, in their migration. It's just a work in progress since it's such a complete overhaul, putting them on Sirev, and basically putting them on many other travel industry search engines that they weren't on before - so, when everything gets sorted, it will be worthwhile. Just very painful now.
I can tell you that other company system overhauls have also been painful. Few overhauls have been as extensive as Westjet's, but the migration is always a huge headache.
I do understand the frustration, believe me, cause I've had some long long delays, and issues in trying to resolve client problems/ bookings/ changes. ; But, I really LOVE Westjet. My own personal experiences with them have made me a devoted fan - if I have the option to fly Westjet, I will take it. ;
My family did a cruise to Alaska last summer. We did a hopper flight from Anchorage to Vancouver with AC - one of the most awful experiences I've ever had with air crew. Then we had a flight from Vancouver to Calgary with Westjet, that was to continue on to Ottawa. Unbeknowst to us, our 2 year old had developed an ear infection, and it made itself known big time on the flight from Vancouver. She started thrashing about, wailing in pain, and we didn't know how to calm her (terrifying as a parent). Obviously, she disturbed everyone on the plane. ; The pilot was worried she'd perforated an eardrum. He ensured we were the first off the plane, we were met by paramedics who'd riden thru the airport on bikes, our DD2 was assessed and transported to the Calgary children's hospital by ambulance (and on the ride, her anxiety caused abnormal heart rhythms which had the EMS gang doing somersaults), ER paramedic diagnosed the ear infection and relieved heart fears (anxiety can do that to agitated toddler, it seems), gave us medicine, and cleared us for flight the next day.
Here's what Westjet did that had made me a life fan .... They gave us a taxi chit for the ride from the hospital to the hotel, put us up an airport hotel for the night, gave us vouchers for breakfast, and had us on another flight to Ottawa the next morning. When we got home in Ottawa, we had a phone call from them to see if she was ok. ; I was/ and still am astounded by that customer service. ; For it to have happened on the heels of the worst experience I've had with an airline only underscored just how wonderful Westjet is.
So - yeah, the overhaul of their computer systems is a MAJOR pain, and it's a bit of a nightmare right now. But, Westjet certainly has a lot more in the emotional bank with me. ; I recommend you wait out this transition period, and give them another try, Alex - you might be pleasantly surprised!