extremely unprofessional and bad service

On 02/11/2018 we bought a flexilamp from Planet Nails Tygervalley. Less than a month later we started having problems with it, the main one that it would not stay on, kept switching off. As there was a six-month guarantee, we took it back to them on 18/12/2018 to be replaced. They checked the lamp and found my complaint to be valid. We were then told that the lamp would have to be sent to Headquarters and they would courier it to Jo'burg on the 19th (the next day) and we would get the lamp returned fixed or replaced on the 26th and they would phone us when it was ready. The 26th being a holiday, we expected a call on the 27th; this did not happen. On the 28th we went to the shop to find out what was happening and were then told that headquarters had closed for the season and we will only get the lamp back on 02/01/2019. Again no phone call from them so we went there again and was then told that "the girl that used to work with us never sent the lamp" and that they would courier it straight away and we would get the lamp back 09/01/2019. Again no notification from them so we phoned again and was then told that "the courier was two days late in picking the lamp up so the lamp will only be ready next week". So now we have to wait another week+ and hope we finally get the lamp replaced. We think that this "after-sales service" is absolutely disgusting, especially with all the finger-pointing and buck-passing, (not to mention the petrol and telephone costs we incurred) and wonder if (when we get the lamp back) there will be a new guarantee starting from the date we receive the new (or repaired) lamp back.