Get them to do a history report on your record locator - it will show the flights and class taken if it was an AC flight you travelled on. The e-ticket may not have been reissued if UA just signed the coupons over to AC and didn't reissue, so it would still be showing the original routing. If they did reissue it, it's something to work with but a history of your booking should show the actual flight and class travelled. As it was an AC flight, does the automated credit miles function in Aeroplan help you any??