Error at checkout

When I try to order the Duo, I receive an error message saying “Only -125 items left in stock”, and it doesn’t let you move forward.

Also, there is a bug when you add to cart, it adds 126 items at once, but the error message remains even when you reduce it to one item.

I tried contacting your support, but with no response. When should I expect it to be resolved? (If it’s just out of stuck, I would suggest a different approach).