I bought a Zip Navigator November 2021. I’ve used it 4 times. The left rear wheel caught a small twig which I immediately removed. The wheel locked up and would not operate. I was unable to disengage and push the cart. Now I’m really livid. Then I get home I use a wheel puller and get the defective wheel off. I had to use emery on the the shaft to remove a gouge. I tried to smooth the bore on the wheel but even with Never Seize lubricant will it come off easily. So after calling customer service ( I use the term loosely) it’s suggested I buy a new wheel. No warranty?