You CAN block calls to a cell. Many smart phones come with a call blocking app already installed. Or you can download a free one. For an older type cell phone ask your carrier. For any cell phone you can put the pest in your contacts list and give them the ring tone "no ring" or "silence". That won't stop the calls but it will make them easier to ignore.
This a spoofed number. Called my cell phone. Recorded message about thanking for being such a good customer (no company named) and offering reward or free food and drink (unspecified place). Verizon indicates it's not a working number (well, at least not in THIS country, apparently).