Sleep Country Canada

I am living in a nightmare for almost 10 days now. I purchased a Serta perfect sleeper on Jan 15 that the salesperson said was great. I told him I have back issues. It arrived on Sat/Jan 18, 2020 and I aired it out for a day because of the 'new smell' and slept on it for only 3 hours on Sun/Jan 19. it was so hard like a board I was in pain. I went to the store on Mon/Jan20 after work and the salesperson recommended i choose another mattress, the Kingsdown. I had to pay $50. (and my receipt does not reflect the taxes which he promised to fix but has not) and they would deliver it on Sun/Jan 26. Just after 1pm on Sunday they delivered the mattress and put
it on the bed. I opened the window to air it out and went on to do other
things. At 7pm I went to my bedroom to see if there was any heavy 'new smells' and look at the Mattress. I had a bit of a shock as it was sinking in the middle and there was no 'new smell' it smelled like a steam cleaning product. Like when I have my rugs and sofa cleaned. This is not a new
mattress! It is a used one. I used a piece of wood to see how much it was sunk and took some photos with my cell ph. as I do not have a digital camera. I called customer Service Sun/Jan/26 at approx. 7:30 pm and was told to send the photos by email. This is a used mattress. I am told it went to the management team and that the CS person is not off until Friday. Any advice to get this resolved?