Paid in Feb, still not done the work

I requested a quote in Feb for cleaning up one of our properties gardens. I accepted the quote and even paid the deposit in Feb. Since then it is impossible to reach anyone and all the telephone no's for them are invalid. I try daily to reach Brian on his cell but no one answers or if they do I get told to phone back in 30 min and when I do no one answers. I have left voice mails etc, emailed them NO LUCK. Absolutely terrible conduct on their behalf.