Poor service

I bought a shed from Riverhorse valley branch, paid for them to come and assemble it, the failed to advise the assembly team so they didn’t arrive in the day that I had booked them. I rebooked and the team arrive late then they inform me that the shed has to be assembled on a slab of concrete! Nowhere on builders warehouse online where i purchased the Keter shed does it say anything about the fact that this had to be assembled on a slab of cement. Now builders have the cheek to want to charge me a call out for them to come back to assemble the shed and still nowhere does it say anything about assembling the shed on concrete. Really poor advertising, poor service, poor advice. You can fetch your shed and refund me I will purchase this elsewhere. Absolutely awful service