Non-Functioning item purchased via contractor

[romeogolf]

My grandparents were looking to fit a security light on the front of their house. They'd picked up the business card of an electrician in a local electrical wholesaler and discussed with him their requirement for a new light. In the process, they were up-sold a Wi-Fi connected lights-and-camera device. The exact timeline of events here I'm not sure on, largely because my grandad has a habit of lying, especially when he realises he's made a mistake, but this is the summary of what followed as best I understand it.

The electrician installed an outdoor socket to the front of their house and plugged in the camera/light unit. He installed an app on my grandmother's phone and explained she could use it to view the camera. He struggled to set this up and left them with just the lights working. Despite a few calls back and forth, plus a replacement camera/light unit, they were left with just the light functionality. The electrician gave the explanation that their Wi-Fi signal was too weak to reach the front of the house, so the camera wouldn't work. This was in October.

Over Christmas my grandparents mentioned it to me and my partner and we said we'd take a look - If it was just a weak signal we could get them a relatively inexpensive network extender and get it working. A few days after Christmas we went over and took at a look. Both the device and the app felt cheap and the instructions were poorly translated from their initial language, but we agreed that the Wi-Fi signal near their front door was very weak and an extender might be the right choice to get it working. The app always hung on the "connecting" screen so this felt logical.

We don't live locally, so gave them the details of a Wi-Fi extender they could buy and said we'd set it up on our next visit. That visit was this weekend and despite a strong Wi-Fi signal, the device still doesn't work. We're pretty sure (based on reviews and my partner's knowledge of iOS apps) that the app is outdated and simply doesn't work. They will never be able to view the camera.

I suggested we take the device down, package it up, and return it to the wholesaler for a refund. At this point it was explained that the device was bought by the electrician who now no longer answers his phone (and searching his name online finds no result for an electrician of that name). It transpires that my grandad has been back to the wholesaler to try and get further details of the electrician but the staff there don't know him and said he just dropped in and left some cards on the desk.

In short, they have been sold a poorly designed item and can't get hold of the person from whom they bought it. Naturally, they paid in cash and don't have an invoice/receipt.

I'm just wondering if there are any options available to them at this point. They are certain the device was purchased from the local wholesaler, but I'm not sure if they have any right to a refund without a receipt, not least as they didn't purchase the device there. Does the retailer have any obligation to replace an apparently faulty device and at what point would it be agreed that the model in question is not fit for purpose and a refund should be provided?

If anyone has any ideas I'd be glad to hear them. Thank you!

(If I'm allowed to post the model of the device it's this, but understand if mods will want to delete it: https://www.ener-j.co.uk/products/view/independent...