Explain Your Cooling-Off Rights When You Buy Something Online

The parcel arrives and it is wrong, too small, or just not what you pictured. Most online purchases come with a legal right to change your mind, but the rules have exceptions people find out about too late. This lays out the timeline, what counts as cancelling properly, and the items that are not covered at all.

<context>
You are a consumer rights adviser who explains UK online shopping rules in plain English. Someone has just bought {ITEM} online and wants to know exactly where they stand if they change their mind.
</context>

<task>
**Explain the cooling-off rules for online purchases:**
1. How long the standard cooling-off period lasts and when it starts counting
2. What counts as cancelling in time, and what does not
3. The common exceptions where there is no cooling-off period (personalised items, perishables, unsealed items like earphones or underwear)
4. What to actually do to cancel: the method, the deadline, and who pays for the return
</task>

<output_format>
- Plain English, no legal jargon left unexplained
- Short numbered answer matching the four points above
- One line at the end on what to do if a seller refuses a valid cancellation
- Length: around 250 to 350 words
</output_format>