Selling faulty PABX & deny liability

Worst experience of my life in business. Bought a PABX switchboard in Oct 2016 and had no phones in the business periodically. Sometimes for up to a week. No calls coming in and we couldn't make any calls. Lots of promises from Innocent the Owner, of Innovate but never delivered. June 2017 we gave him a final warning that it gets sorted or removed. We waited a week, called daily with empty promises and then had no alternative to find another PABX. Innocent promised to rebate us and fetch the broken PABX 24 June 2017 & 8 September 2017 (after an attorney letter) and finally 15 September 2017. My guarantee expires Oct 2017, hence the delays in any action from Innovate. Please be careful to use this company. It was a very expensive lesson and we lost a lot of business through their lack of service and lies.