Sanders & Associates, cisco_deals Chip Sanders, selling electronics hardware has no function at all Newnan, Georgia

We purchased a POLYTEC OFV-1102 Laser vibrometer from Ebay, where the seller, chip sander, (ebay ID: sisco-deals) claimed it "fully functional". We ( a university in orlando) paid this units in full (~3000$). The unit did NOT work, the indicator came on but no laser output. We asked a return due to no laser came out and he agreed to refund (Return merchandise authorization: RMA)  RMA # MK1302271 was issued (which seller agreed refund over the phone).  Then he BEGGED US to find a professor to had a look (we have the best optical scientist in the world). Then we HAD to ask our professor (Prof Chang) to had a look. And
the professor examined the top cover and made test on power supply outlet by a voltage meter and a power meter to conclude that his units is not working due to dead power supply component. We shipped it back immediately (27th, Feb) and told him this is a troublesome units and has no value.

Chip Sander, procrastinated our communications, on today (Mar 19th), after knowing our opinion on this units, he expressed that he had no intention to refund us at all. The seller, Chip Sander, claimed that his
"labels was tampered" and refused to refund. Then we filed claim against him on Ebay. Ebay supported our claim, unfortunately, Chip avoided the payment escrow of Ebay and he acquired our money into his bank account. The seller claimed "fully functional", it has no function AT ALL. 2803$ loss.