Left with the job unfinished and a bad taste in my mouth

They came and viewed the site and examined the trees. They followed up with a quote which specified the price and that they would need a Friday and part of the Monday to do the job. Friday came and they arrived and did the bulk of the work. Monday came and they arrived in the afternoon as they'd promised. By the end of the day there were still two big tree stumps left. They said that they can't spend any more time there and returned 30% of my payment. Absolutely useless! I was happy to spend the money and I needed the stumps gone so that I can build there. So now I've got a problem. Imagine if everyone just left their work unfinished when they decided it was too difficult?