What should I do?

I signed a contract with a roofing company in November, paid my 50% deposit.

Was told probably would get to it after first of the year. I was totally fine with that. I don't expect the roof to be done in the winter and appreciated the fact that they didn't try. They finally called early April, they had come by with a couple of the crew to check out the job, told me they would get in the following week. I heard nothing after that. I called about 2 weeks later got no response. Again waited about 3 weeks and called again., this time was told it would be later that week or the following week. The following week it rained, so expected something the next week. Nothing. I tried to call again Monday, but have not heard back. Am I being impatient? What should I do?