[Your address and contact number]
[Reference: order number]
On [date], I bought/placed the above order with you for [item]. The [item] has still not been delivered.
We agreed at the time I placed the order that it would arrive [on date / within timeframe].
Under the Consumer Rights Act you are required to deliver the [item] to me at the agreed time. As I have still not received [item], and it is past the agreed time, I believe you’re in breach of contract.
I made it known to you that it was essential that [item] be delivered to me by [on date / within timeframe].
It should have been obvious that delivery of [item] by this deadline was essential.
As it was essential for me to receive the [item] by [date] and it has not been delivered, I consider our contract at an end and will expect you to refund me the full purchase price of [£xx].