Returning something with no tags due to wildly inaccurate sizing, is it possible?

So, I recently ordered a pair of Align leggings from the lululemon Canada site. Looking at the size chart, I saw that size 20 (sorry for being fat in here lol) was for a 43" waist. I am currently a 46"ish inch waist, I know this because I am losing weight and tracking my measurements weekly. I figured that I would buy the 20s since I had a gift certificate and might fit in them eventually due to the whole weight loss thing.

I am stupid and took the tags off when I bought them cause they were cute and I was excited. But omg when I very carefully tried them on, they were wildly too loose. These fit looser by far than my Old Navy 2x leggings (which are for 42-44" waist and fit me tight but don't roll down) and to be honest fit very similarly to my size 24 leggings from a plus size store that I no longer wear due to falling off.

Is there any hope I can return them? They were full price. I feel like since they do not carry plus sizes in store really where I am, the only way I can order for myself is by following the size chart. But the size chart seems to be wildly inaccurate.

Thanks for any help you can give. I really like the fabric and might give the lulus another go but this was super demoralizing lol.