Performance Truck Outfitters

In August of 2016, after explaining that we were about to leave for Indiana for college and needed something that could sustain extreme temperatures, we purchased a truck bed cover from Performance. On the invoice, which we kept and still have, there is listed a BakFlip MX4 2008 Chevrolet Silverado 6.6ft as well as installation and Pop n' Lock PL. 
The cover we are invoiced for has a 5 year warranty.
When the polar vortex came through Fort Wayne, Indiana, where we were away at college, in 2019, the plastic clips and rubber joints on the cover we have were ruined. Once we got back to Oklahoma this summer, we called Performance and scheduled a time to come up and get it fixed.
When we went in this morning, we were told that the cover we are invoiced for is not the cover they put on, the cover on currently cannot be repaired and needs to be completely replaced, and that the cover they put on has a 3 year warranty and there is nothing they can do.
Upon returning home and looking up the warranty policies for both the cover we were invoiced for and the cover we actually have, we found out about the five year warranty we should have according to the invoice and called Performance to ask what they were going to do to make it right.
We were told that we should have researched it ourselves to see what cover could sustain a polar vortex (as if we knew there would be one and as if we hadn't explained to Performance where we would be), told that it is the customer's responsibility to make sure we are invoiced for the correct item, and told to take them to small claims court before they hung up on us. 
We spent $1,015.80 on a truck bed cover that got 1 to 2 uses a year and is now completely useless to us less than 4 years later. We paid for a cover with a 5 year warranty and are being told the incorrect invoice is our fault.
I have no idea why or how Performance is still in business with the way they speak to their customers; screaming,  name-calling, and hanging up on people.