I went through about the same thing with a Sears lawnmower.It just happened to be a "lemon" and I made complaints, took it back 4 times for repairs.
It never did work. I complained to several managers, too. Even the district manager and their main office. It was under warranty when I first took it in but after 12 weeks of back and forth to the repair shop, the shop wanted to charge me.
I said it was under warranty when I first brought it in for repairs. It had not been repaired. The store manager called the main office and he looked up on his computer and saw how things had gone. Not only that, I lived in a small town and I had to drive 45 miles each way to a Sears repair shop.
The lawnmower was never repaired, they would not replace it, and I ended up with a credit card bill for a product that never worked. By then the grass was so high I had to hire someone to come and mow it. Another expense.
He continued to do the lawn care until I moved.
Review about: Sears Repair.