Firstly the tyres didn't turn up when they said they would.. they were several days late!
The customer support was dire.. they tried to blame the fitment station for their late delivery. No apologies, nothing!
They refused to honour the cashback, and even when challenged still wouldn't budge despite having spent over £500 on tyres from them. Some nonsensical reason not to pay was suggested by Quidco. From other reviews it would seem I'm not the only one to suffer the same treatment.
I again contacted their customer service over none payment of the cashback and general poor service, and they couldn't even be bothered to reply.
Have since found out this company is a trading brand of Delti.com which also runs mytyres.co.uk so be warned!