Bed Bath & Beyond

I purchased an aero mattress on 11/24/2020. I was told by the cashier I had 90 days to return the mattress. The mattress is horrible. I sat on it and it was like a big plastic brick. I went to return it and I was told by the mgr at bed bath and beyond - 1490 Union Turnpike, NHP, NY - that it was not returnable. I told him that was not what was told to me when I purchased it - I was promised that if it was returned within 90 days with a receipt. His response was "We won't take it back, there are signs all over. There are NO signs posted. I will never shop at BB&B again, I will be filing a complaint with the Better Business Bureau., and I will share with people I know my experience at this store location. You have caved to cancel culture and are disloyal to you customer base — done with your stores and online purchases too.
P.S. — The store mgr is rude and obnoxious — I am done with you.