2019 Aqa Law Question Help

hi guys, i’m doing a practice question on CRA and I’ve managed to do the Consumer Rights bit, but I’m stuck on what cases apply from Exemption Clauses, I was thinking of CHAPELTON v BARRY but would that still apply because of the invoice or is that for only receipts? If anyone could help it would be appreciated thank you!

‘Hal bought a £200 tent from Outward, a local store, in preparation for a summer camping holiday. He did not check the tent until the day before he was due to leave, when he found that it was badly made and would not stay up. Fortunately, his next-door neighbour, Jed, was able to lend him a suitable tent.

When Hal returned from holiday after six weeks, he took the tent back to Outward who said that there was nothing they could do because he had signed an invoice which stated that goods could only be returned if a fault was reported within 21 days.’